diff --git a/src/__tests__/notification-delivery-identity.test.ts b/src/__tests__/notification-delivery-identity.test.ts
index c143bcbc5..572c0c28a 100644
--- a/src/__tests__/notification-delivery-identity.test.ts
+++ b/src/__tests__/notification-delivery-identity.test.ts
@@ -60,12 +60,9 @@ const recipientUserId = "guardian-recipient";
 
 beforeEach(() => {
   vi.resetAllMocks();
-  vi.mocked(prisma.user.findUnique).mockImplementation(async (args) => {
-    const id = (args as { where: { id: string } }).where.id;
-    return id === recordUserId
-      ? ({ managedProfileAt: new Date() } as never)
-      : (null as never);
-  });
+  vi.mocked(prisma.user.findUnique).mockResolvedValue({
+    managedProfileAt: new Date(),
+  } as never);
   vi.mocked(prisma.notificationChannel.findMany).mockResolvedValue([
     {
       id: "recipient-channel",
diff --git a/src/app/api/admin/notifications/diagnostic/route.ts b/src/app/api/admin/notifications/diagnostic/route.ts
index 9c80e4df9..1e2be30b7 100644
--- a/src/app/api/admin/notifications/diagnostic/route.ts
+++ b/src/app/api/admin/notifications/diagnostic/route.ts
@@ -59,6 +59,8 @@ interface DiagnosticChannel {
 }
 
 interface DiagnosticPushAttempt {
+  recordUserId: string;
+  recipientUserId: string;
   eventType: string;
   channel: string;
   result: string;
@@ -170,18 +172,23 @@ export const GET = apiHandler(async () => {
       where: { userId: user.id },
       select: { type: true, enabled: true, config: true },
     }),
-    // v1.4.49 — trailing 20 push attempts for the calling admin's own
-    // account. The `(user_id, created_at DESC)` index on `push_attempts`
-    // turns the orderBy + take into a single index scan, so the cost is
-    // bounded regardless of the user's lifetime push volume.
+    // Trailing delivery attempts for the calling account as recipient. The
+    // recipient index keeps the bounded diagnostic read independent of the
+    // account's lifetime notification volume.
     prisma.pushAttempt.findMany({
       // The reminder tick's per-slot dedup anchors live in this table under
       // a sentinel channel. They are bookkeeping, not delivery attempts,
       // and would push the real sends out of the trailing window.
-      where: { userId: user.id, channel: { not: REMINDER_DEDUP_CHANNEL } },
+      where: {
+        recipientUserId: user.id,
+        channel: { not: REMINDER_DEDUP_CHANNEL },
+      },
       orderBy: { createdAt: "desc" },
       take: 20,
       select: {
+        userId: true,
+        recordUserId: true,
+        recipientUserId: true,
         eventType: true,
         channel: true,
         result: true,
@@ -215,6 +222,8 @@ export const GET = apiHandler(async () => {
   // `DiagnosticPushAttempt` interface above (the existing consumer
   // contract uses `at`, not `createdAt`).
   const recentPushAttempts: DiagnosticPushAttempt[] = pushAttempts.map((a) => ({
+    recordUserId: a.recordUserId ?? a.userId,
+    recipientUserId: a.recipientUserId ?? a.userId,
     eventType: a.eventType,
     channel: a.channel,
     result: a.result,