diff --git a/backend/src/modules/timers/routes.ts b/backend/src/modules/timers/routes.ts
index 80085dc..160bacd 100644
--- a/backend/src/modules/timers/routes.ts
+++ b/backend/src/modules/timers/routes.ts
@@ -150,7 +150,7 @@ export async function timerRoutes(app: FastifyInstance) {
     const active = timers.filter(t => t.state === 'active' || t.state === 'warning').length;
     const pending = timers.filter(t => t.state === 'paused').length;
     const lastSyncedAt = timers[0]?.lastSyncedAt ?? null;
-    const conflictCount = timers.filter(t => t.syncVersion === 0).length;
+    const unsyncedCount = timers.filter(t => t.lastSyncedAt == null).length;
 
     return {
       userId: auth.sub,
@@ -158,7 +158,7 @@ export async function timerRoutes(app: FastifyInstance) {
       totalTimers: timers.length,
       active,
       pending,
-      conflictCount,
+      unsyncedCount,
       lastSyncedAt,
       generatedAt: new Date().toISOString(),
     };
diff --git a/web/src/lib/diagnostics.ts b/web/src/lib/diagnostics.ts
index 5e58865..17ae1cb 100644
--- a/web/src/lib/diagnostics.ts
+++ b/web/src/lib/diagnostics.ts
@@ -31,12 +31,17 @@ export function initDiagnostics(): void {
     buildNumber: process.env.NEXT_PUBLIC_BUILD_NUMBER ?? '1',
     releaseChannel: process.env.NEXT_PUBLIC_RELEASE_CHANNEL ?? 'beta',
     serverUrl: getBaseUrl(),
-    getAuthToken: () => getAuthClient().getAccessToken() ?? undefined,
+    getAuthToken: () => {
+      const token = getAuthClient().getAccessToken();
+      if (!token) throw new Error('unauthenticated');
+      return token;
+    },
     captureConsole: true,
     captureErrors: true,
     captureNetwork: false,
     pollIntervalMs: 30_000,
-  }).start();
+  });
+  void DiagnosticsClient.getInstance().start();
 }
 
 export function stopDiagnostics(): void {