diff --git a/src/app/api/dashboard/widgets/__tests__/route.test.ts b/src/app/api/dashboard/widgets/__tests__/route.test.ts
index 5611f3fc3..258346380 100644
--- a/src/app/api/dashboard/widgets/__tests__/route.test.ts
+++ b/src/app/api/dashboard/widgets/__tests__/route.test.ts
@@ -62,7 +62,13 @@ import {
   DASHBOARD_WIDGET_IDS,
   DASHBOARD_IOS_ONLY_WIDGET_IDS,
   DASHBOARD_WIDGET_CATALOGUE_IDS,
+  DEFAULT_DASHBOARD_LAYOUT,
   serializeDashboardLayout,
+  // v1.32.1 — the exact payload builder `ringMutation.mutationFn` calls
+  // (see the settings component). Importing the shipped function rather
+  // than re-implementing its shape means this test exercises the REAL
+  // client contract against the REAL route, not a hand-rolled stand-in.
+  buildRingMutationPayload,
   type DashboardLayout,
 } from "@/lib/dashboard-layout";
 
@@ -636,3 +642,102 @@ describe("dashboard widgets — preserve-when-absent on PUT", () => {
     }
   });
 });
+
+/**
+ * v1.32.1 — regression for issue #581: dashboard layout changes silently
+ * overwritten by a concurrent score-ring save.
+ *
+ * The scenario from the report: the user edits tile/chart visibility
+ * (local draft B), then reorders/toggles a hero score ring before hitting
+ * Save. The ring PUT (`ringMutation`) fires immediately, built from
+ * whatever layout the client had cached (layout A — the state BEFORE the
+ * draft edit). The normal Save button then PUTs the full draft (layout B)
+ * and commits first. If the earlier-fired ring request resolves AFTER
+ * Save, its body — built from the stale A snapshot — used to carry
+ * `widgets: A` explicitly, and an explicitly-present field always wins on
+ * write. Save's B silently reverted to A even though the ring PUT reported
+ * 200 and only meant to touch the ring selection.
+ *
+ * The fix is `buildRingMutationPayload` (imported from the real component
+ * module, not re-implemented here): it never includes `widgets` at all.
+ * This test proves the SERVER half of the fix — a PUT shaped exactly like
+ * the shipped ring mutation's body preserves whatever layout is CURRENTLY
+ * stored, so the request that resolves last can no longer matter.
+ */
+describe("dashboard widgets — ring-only PUT cannot race a concurrent full-layout Save (regression #581)", () => {
+  it("preserves the widgets a concurrent Save already committed, even though the ring request started from a stale snapshot", async () => {
+    // The state AFTER the normal Save committed layout B — a tile turned
+    // off that was on in the stale snapshot A the ring mutation started
+    // from. Starts from the FULL default widget catalogue (rather than a
+    // single-widget array) so `resolveDashboardLayout`'s auto-upgrade
+    // append (missing catalogue ids get seeded invisible) is a no-op here
+    // and the persisted array can be compared for exact equality below.
+    const savedLayoutB: DashboardLayout = serializeDashboardLayout({
+      version: 1,
+      widgets: DEFAULT_DASHBOARD_LAYOUT.widgets.map((w) =>
+        w.id === "weight" ? { ...w, visible: false, tileVisible: false } : w,
+      ),
+      comparisonBaseline: "lastYear",
+      selectedScoreRings: ["MED_COMPLIANCE"],
+      heroRingOrder: ["HEALTH_SCORE", "MED_COMPLIANCE"],
+    });
+    vi.mocked(prisma.user.findUnique).mockResolvedValue({
+      dashboardWidgetsJson: savedLayoutB,
+    } as never);
+    vi.mocked(prisma.user.update).mockResolvedValue({} as never);
+
+    // The ring mutation's real, shipped payload — built without any
+    // knowledge of layout B. If this were still `{...staleA, ...}` the
+    // stale `widgets`/`comparisonBaseline` would land here explicitly and
+    // overwrite B; `buildRingMutationPayload` never carries them.
+    const ringOnlyBody = buildRingMutationPayload({
+      selectedScoreRings: ["READINESS"],
+      heroRingOrder: ["HEALTH_SCORE", "READINESS"],
+    });
+
+    const res = await callPut(makeReq(ringOnlyBody));
+    expect(res.status).toBe(200);
+
+    const updateArg = vi.mocked(prisma.user.update).mock
+      .calls[0]?.[0] as unknown as {
+      data: { dashboardWidgetsJson: DashboardLayout };
+    };
+    // B's widgets (and comparisonBaseline) survive — the ring PUT never
+    // touched them, so nothing it carries can outrace the Save that
+    // already committed.
+    expect(updateArg.data.dashboardWidgetsJson.widgets).toEqual(
+      savedLayoutB.widgets,
+    );
+    expect(updateArg.data.dashboardWidgetsJson.comparisonBaseline).toBe(
+      "lastYear",
+    );
+    // The ring selection itself DID apply.
+    expect(updateArg.data.dashboardWidgetsJson.selectedScoreRings).toEqual([
+      "READINESS",
+    ]);
+
+    const body = (await res.json()) as { data: DashboardLayout };
+    expect(body.data.widgets[0].visible).toBe(false);
+    expect(body.data.widgets[0].tileVisible).toBe(false);
+    expect(body.data.selectedScoreRings).toEqual(["READINESS"]);
+  });
+
+  it("still accepts a normal full-layout Save (widgets present + replace semantics unchanged)", async () => {
+    vi.mocked(prisma.user.findUnique).mockResolvedValue({
+      dashboardWidgetsJson: null,
+    } as never);
+    vi.mocked(prisma.user.update).mockResolvedValue({} as never);
+
+    const res = await callPut(
+      makeReq({
+        version: 1,
+        widgets: [
+          { id: "weight", visible: false, tileVisible: false, order: 0 },
+        ],
+      }),
+    );
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: DashboardLayout };
+    expect(body.data.widgets[0].visible).toBe(false);
+  });
+});
diff --git a/src/app/api/dashboard/widgets/route.ts b/src/app/api/dashboard/widgets/route.ts
index 790501f5e..d7c8c97f6 100644
--- a/src/app/api/dashboard/widgets/route.ts
+++ b/src/app/api/dashboard/widgets/route.ts
@@ -84,7 +84,15 @@ const layoutSchema = z.object({
     // catalogue (42 ids). The cap only has to clear the catalogue size —
     // the enum bounds each entry and the id set is closed — so it carries
     // headroom rather than tracking the count exactly.
-    .max(50),
+    .max(50)
+    // v1.32.1 — optional + preserve-when-absent (issue #581). The
+    // Settings page's instant score-ring toggle now PUTs ONLY the ring
+    // fields; omitting `widgets` lets the server carry forward whatever
+    // is CURRENTLY stored instead of the ring mutation resending a
+    // client-held snapshot that can go stale mid-flight and race a
+    // concurrent full-layout Save. A normal Save still always sends
+    // `widgets` — this only widens what a PARTIAL PUT can leave out.
+    .optional(),
   // v1.4.16 phase B8 — comparison baseline (Vormonat / Vorjahr) rides
   // on the layout blob per research §7 Q3 (no Prisma migration). Optional
   // so v1.4.15 clients that don't know the field can still PUT.
@@ -285,7 +293,11 @@ export const PUT = apiHandler(async (request: NextRequest) => {
   // visibility / order, while chart prefs are PUT through their own route
   // (`/api/dashboard/chart-overlay-prefs`), the hero rings come from
   // Settings, and `comparisonBaseline` is web-only — an omission from any
-  // one surface must not reset a choice made on another.
+  // one surface must not reset a choice made on another. `widgets` itself
+  // joined this set in v1.32.1 (issue #581): the Settings page's instant
+  // score-ring PUT omits it entirely so it always carries forward
+  // whatever is CURRENTLY stored, rather than a client-held snapshot that
+  // could be stale relative to a concurrent full-layout Save.
   //
   // The preserve set is not a list maintained here: it is derived from
   // `LAYOUT_FIELD_MERGE_DISPOSITION`, which the type system forces to cover
diff --git a/src/components/settings/__tests__/dashboard-layout-section.test.tsx b/src/components/settings/__tests__/dashboard-layout-section.test.tsx
index 1be642928..33eaa1ea4 100644
--- a/src/components/settings/__tests__/dashboard-layout-section.test.tsx
+++ b/src/components/settings/__tests__/dashboard-layout-section.test.tsx
@@ -69,10 +69,7 @@ vi.mock("@/hooks/use-auth", () => ({
 }));
 
 import { I18nProvider } from "@/lib/i18n/context";
-import {
-  DashboardLayoutSection,
-  reorderWidgets,
-} from "../dashboard-layout-section";
+import { DashboardLayoutSection, reorderWidgets } from "../dashboard-layout-section";
 
 function render(node: React.ReactElement, locale: "en" | "de" = "en") {
   return renderToStaticMarkup(
@@ -531,4 +528,19 @@ describe("<DashboardLayoutSection> — health-score anchor + reorder (v1.27.27)"
     // The order is the single source of truth: selection is derived from it.
     expect(src).toMatch(/id !== HEALTH_SCORE_RING_ID/);
   });
+
+  it("the ring mutation builds its body via buildRingMutationPayload, not a `...remote` spread (regression #581 source pin)", () => {
+    const src = readFileSync(
+      join(
+        process.cwd(),
+        "src/components/settings/dashboard-layout-section.tsx",
+      ),
+      "utf8",
+    );
+    expect(src).toContain("buildRingMutationPayload(next)");
+    // The pre-fix shape must never come back: spreading a query-cache
+    // snapshot into the ring PUT body is exactly the stale-`widgets`
+    // race issue #581 reported.
+    expect(src).not.toMatch(/\.\.\.remote,/);
+  });
 });
diff --git a/src/components/settings/dashboard-layout-section.tsx b/src/components/settings/dashboard-layout-section.tsx
index 20a4bb507..ddaf3bd5e 100644
--- a/src/components/settings/dashboard-layout-section.tsx
+++ b/src/components/settings/dashboard-layout-section.tsx
@@ -47,6 +47,7 @@ import {
   MAX_SELECTED_SCORE_RINGS,
   HEALTH_SCORE_RING_ID,
   resolveHeroRingOrder,
+  buildRingMutationPayload,
 } from "@/lib/dashboard-layout";
 import {
   Select,
@@ -327,23 +328,34 @@ export function DashboardLayoutSection({ id }: { id: string }) {
    * machine the rest of the section keeps. The first cut routed ring
    * toggles through the draft, and the combination of an unflushed
    * draft, the server snapshot cache, and client staleness read as
-   * "flipping does nothing, rings appear later". The mutation PUTs the
-   * SERVER layout copy with only `selectedScoreRings` changed (an open
-   * draft's other edits stay unsent and untouched), optimistically
-   * updates the widgets query, and invalidates the dashboard snapshot on
-   * settle so the hero reflects the choice on the next visit.
+   * "flipping does nothing, rings appear later". The mutation
+   * optimistically updates the widgets query and invalidates the
+   * dashboard snapshot on settle so the hero reflects the choice on the
+   * next visit.
+   *
+   * v1.32.1 — the PUT body used to be the FULL server layout copy,
+   * spreading this component's `remote` query-cache snapshot in ahead of
+   * the two ring fields. That snapshot can be stale by the time the
+   * request actually lands: if the normal
+   * tile/chart Save button committed a newer layout first, this
+   * request's explicit — present, not omitted — stale `widgets` (and
+   * `comparisonBaseline` / `chartOverlayPrefs`) still won on write and
+   * silently reverted the just-saved layout (issue #581). The payload
+   * now carries ONLY the ring fields; the server's preserve-when-absent
+   * merge (`LAYOUT_FIELD_MERGE_DISPOSITION` — `widgets` joined it in the
+   * same release) carries every omitted field forward from whatever is
+   * CURRENTLY stored, so this request can no longer race a concurrent
+   * Save no matter which one lands last.
    */
   const ringMutation = useMutation({
     mutationFn: async (next: {
       selectedScoreRings: ScoreRingId[];
       heroRingOrder: HeroRingId[];
     }) => {
-      if (!remote) throw new Error("layout not loaded");
-      return apiPut<DashboardLayout>("/api/dashboard/widgets", {
-        ...remote,
-        selectedScoreRings: next.selectedScoreRings,
-        heroRingOrder: next.heroRingOrder,
-      });
+      return apiPut<DashboardLayout>(
+        "/api/dashboard/widgets",
+        buildRingMutationPayload(next),
+      );
     },
     onMutate: async (next) => {
       await queryClient.cancelQueries({
diff --git a/src/lib/__tests__/dashboard-layout.test.ts b/src/lib/__tests__/dashboard-layout.test.ts
index 8379f5c0c..0e091ce05 100644
--- a/src/lib/__tests__/dashboard-layout.test.ts
+++ b/src/lib/__tests__/dashboard-layout.test.ts
@@ -13,6 +13,7 @@ import {
   PRESERVED_LAYOUT_FIELDS,
   layoutNeedsPreserveRead,
   mergePreservedLayoutFields,
+  buildRingMutationPayload,
   type DashboardLayout,
 } from "@/lib/dashboard-layout";
 
@@ -1006,20 +1007,24 @@ describe("layout field merge disposition", () => {
     }
   });
 
-  it("preserves comparisonBaseline alongside the other client-owned fields", () => {
+  it("preserves comparisonBaseline and widgets alongside the other client-owned fields", () => {
     // The regression itself: `comparisonBaseline` must be in the preserve
-    // set, not merely present in the disposition map.
+    // set, not merely present in the disposition map. `widgets` joined it in
+    // v1.32.1 (issue #581) — see the dedicated describe block below.
     expect([...PRESERVED_LAYOUT_FIELDS].sort()).toEqual([
       "chartOverlayPrefs",
       "comparisonBaseline",
       "heroRingOrder",
       "selectedScoreRings",
+      "widgets",
     ]);
   });
 
-  it("replaces the fields the request itself owns", () => {
+  it("replaces only the field every request must state", () => {
+    // `version` is the sole `"replace"` field left once `widgets` joined
+    // the preserve set — a PUT that omits it is rejected by Zod, so there
+    // is never a stored value to fall back to.
     expect(LAYOUT_FIELD_MERGE_DISPOSITION.version).toBe("replace");
-    expect(LAYOUT_FIELD_MERGE_DISPOSITION.widgets).toBe("replace");
   });
 
   it("skips the stored-layout read when the client sent every preserved field", () => {
@@ -1086,3 +1091,51 @@ describe("layout field merge disposition", () => {
     expect(merged.widgets).toEqual(fullyPopulatedLayout.widgets);
   });
 });
+
+/**
+ * v1.32.1 — regression for issue #581 (dashboard layout race). The
+ * Settings page's instant score-ring PUT used to resend the FULL layout,
+ * built from the `remote` query-cache snapshot
+ * (`{...remote, selectedScoreRings, heroRingOrder}`). That snapshot can be
+ * stale relative to an in-flight or already-committed tile/chart Save;
+ * because `widgets` was a `"replace"`-disposition field on the server, an
+ * explicitly-present stale copy always won on write and silently reverted
+ * the just-saved layout.
+ *
+ * `buildRingMutationPayload` is the exact function
+ * `ringMutation.mutationFn` (in `dashboard-layout-section.tsx`) calls to
+ * build its request body. Pinning its shape here — no `widgets`, no
+ * `comparisonBaseline`, no `chartOverlayPrefs` — is what makes the race
+ * structurally impossible: a payload that never carries those fields
+ * cannot overwrite them no matter which request lands last. See
+ * `src/app/api/dashboard/widgets/__tests__/route.test.ts` for the
+ * server-side half — a PUT shaped like this preserves whatever layout is
+ * CURRENTLY stored, not a client-held snapshot.
+ */
+describe("buildRingMutationPayload — instant score-ring PUT payload (regression #581)", () => {
+  it("carries only version + the two ring fields", () => {
+    const payload = buildRingMutationPayload({
+      selectedScoreRings: ["READINESS"],
+      heroRingOrder: ["HEALTH_SCORE", "READINESS"],
+    });
+    expect(Object.keys(payload).sort()).toEqual([
+      "heroRingOrder",
+      "selectedScoreRings",
+      "version",
+    ]);
+    expect(payload.version).toBe(1);
+    expect(payload.selectedScoreRings).toEqual(["READINESS"]);
+    expect(payload.heroRingOrder).toEqual(["HEALTH_SCORE", "READINESS"]);
+  });
+
+  it("never includes widgets, comparisonBaseline, or chartOverlayPrefs — the fields a concurrent Save owns", () => {
+    const payload = buildRingMutationPayload({
+      selectedScoreRings: ["READINESS"],
+      heroRingOrder: ["HEALTH_SCORE", "READINESS"],
+    });
+    expect(payload.widgets).toBeUndefined();
+    expect(payload.comparisonBaseline).toBeUndefined();
+    expect(payload.chartOverlayPrefs).toBeUndefined();
+    expect("widgets" in payload).toBe(false);
+  });
+});
diff --git a/src/lib/dashboard-layout.ts b/src/lib/dashboard-layout.ts
index 54447cc5d..4c4e790a4 100644
--- a/src/lib/dashboard-layout.ts
+++ b/src/lib/dashboard-layout.ts
@@ -574,8 +574,8 @@ export interface DashboardLayout {
  * omits it.
  *
  * - `"replace"` — the field is the point of the request. A PUT that omits it
- *   is either rejected by Zod (`version`, `widgets` are required) or means
- *   the caller genuinely has nothing to say.
+ *   is rejected by Zod (`version` is required) — the caller always has
+ *   something to say about a `"replace"` field.
  * - `"preserve"` — the field is owned by a surface OTHER than the one making
  *   this request, so an omission means "I don't know about this", never
  *   "clear it". The route reads the stored layout and carries the existing
@@ -591,6 +591,18 @@ export interface DashboardLayout {
  * clamps a missing value to `"none"`, so every native layout save wiped the
  * baseline the user had picked on the web.
  *
+ * `widgets` moved from `"replace"` to `"preserve"` in v1.32.1 (issue #581).
+ * The Settings page's instant score-ring toggle used to resend the FULL
+ * layout — including `widgets` — built from the query cache's `remote`
+ * snapshot. That snapshot can be stale by the time the ring request lands:
+ * if a normal tile/chart Save committed a newer layout first, the
+ * ring request's explicit (present, not omitted) stale `widgets` value
+ * still won on write and silently reverted the just-saved layout. Making
+ * `widgets` optional + preserve-when-absent lets the ring mutation omit it
+ * entirely, so the field it never touches can no longer race a concurrent
+ * Save — the route always carries forward whatever is CURRENTLY stored,
+ * not a client-held copy.
+ *
  * `satisfies Record<keyof DashboardLayout, …>` is the load-bearing part.
  * Adding a field to `DashboardLayout` without adding it here is a TYPE error,
  * so the next field cannot repeat the `comparisonBaseline` mistake by
@@ -598,7 +610,7 @@ export interface DashboardLayout {
  */
 export const LAYOUT_FIELD_MERGE_DISPOSITION = {
   version: "replace",
-  widgets: "replace",
+  widgets: "preserve",
   comparisonBaseline: "preserve",
   chartOverlayPrefs: "preserve",
   selectedScoreRings: "preserve",
@@ -647,6 +659,38 @@ export function mergePreservedLayoutFields(
   return merged;
 }
 
+/**
+ * v1.32.1 — pure payload builder for the Settings page's instant score-ring
+ * PUT (`ringMutation` in `dashboard-layout-section.tsx`). Lives in this
+ * client-safe module (imported by both the client component and the server
+ * route already) rather than the "use client" component file, so a
+ * server-side regression test can import it without pulling the component's
+ * UI dependency graph across the client/server boundary — see
+ * `src/app/api/dashboard/widgets/__tests__/route.test.ts`.
+ *
+ * Deliberately returns ONLY the ring fields (plus `version`) — no
+ * `widgets`, `comparisonBaseline`, or `chartOverlayPrefs`. Before v1.32.1 the
+ * ring mutation resent the FULL layout built from the client's `remote`
+ * query-cache snapshot, which can be stale by the time the request lands: if
+ * a normal tile/chart Save committed a newer layout first, the ring
+ * request's explicit — present, not omitted — stale `widgets` still won on
+ * write and silently reverted the just-saved layout (issue #581). Those
+ * three fields are all `"preserve"`-disposition here
+ * (`LAYOUT_FIELD_MERGE_DISPOSITION`): omitting them means the route always
+ * carries forward whatever is CURRENTLY stored, so this payload can no
+ * longer race a concurrent Save no matter which request lands last.
+ */
+export function buildRingMutationPayload(next: {
+  selectedScoreRings: ScoreRingId[];
+  heroRingOrder: HeroRingId[];
+}): Partial<DashboardLayout> {
+  return {
+    version: DASHBOARD_LAYOUT_VERSION,
+    selectedScoreRings: next.selectedScoreRings,
+    heroRingOrder: next.heroRingOrder,
+  };
+}
+
 const DASHBOARD_LAYOUT_VERSION = 1;
 
 /**