diff --git a/src/App.tsx b/src/App.tsx
index 951af33..2fc0f78 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -10,7 +10,7 @@ import { TopBar } from './components/TopBar';
 import { ProductDescriptions } from './components/ProductDescriptions';
 import { MatrixView } from './components/MatrixView';
 import { EditPanel } from './components/EditPanel';
-import { getAllSyncedRows, saveRowToSupabase, saveHistoryEntry, deleteHistoryEntry, getHistoryDataForMerge } from './lib/supabase';
+import { getAllSyncedRows, saveRowToSupabase, saveHistoryEntry, deleteHistoryEntry, getHistoryDataForMerge, safeFetch } from './lib/supabase';
 import { getStoredSession, signOut, type AuthSession } from './lib/auth';
 import { LoginPage } from './components/LoginPage';
 import { DimensionsView } from './components/DimensionsView';
@@ -124,7 +124,7 @@ export default function App() {
 
     const checkUserStatus = async () => {
       try {
-        const res = await fetch('/api/users-admin', {
+        const res = await safeFetch('/api/users-admin', {
           method: 'POST',
           headers: {
             'Content-Type': 'application/json',
@@ -136,8 +136,12 @@ export default function App() {
         if (!isMounted) return;
 
         if (!res.ok) {
-          console.warn('[App] Validation check failed, logging out.');
-          handleSignOut();
+          if (res.status === 401 || res.status === 403) {
+            console.warn('[App] Session is no longer valid, logging out.');
+            handleSignOut();
+          } else {
+            console.warn('[App] Validation check temporarily unavailable:', res.status);
+          }
           return;
         }
 
@@ -154,8 +158,8 @@ export default function App() {
     // Check immediately on mount/session change
     checkUserStatus();
 
-    // Check periodically every 5 minutes
-    const interval = setInterval(checkUserStatus, 5 * 60 * 1000);
+    // Check periodically, but keep it lightweight to avoid interrupting work.
+    const interval = setInterval(checkUserStatus, 30 * 60 * 1000);
 
     return () => {
       isMounted = false;