diff --git a/src/components/payment/PaymentHistory/PaymentHistory.tsx b/src/components/payment/PaymentHistory/PaymentHistory.tsx
index a0899901..65c3d4ab 100644
--- a/src/components/payment/PaymentHistory/PaymentHistory.tsx
+++ b/src/components/payment/PaymentHistory/PaymentHistory.tsx
@@ -70,19 +70,38 @@ export const PaymentHistory: React.FC<PaymentHistoryProps> = ({
 
   // Fetch payment history (uses authenticated user). Extracted as a stable
   // callback so the realtime hook can re-run it on a payment_results change.
+  //
+  // Retries transient failures before surfacing the error alert. The query
+  // runs right after auth/session hydration; under load (e.g. Supabase
+  // Realtime/RLS returning a transient 401/406 during a session refresh) the
+  // FIRST attempt can throw even though a retry a moment later succeeds.
+  // Without this, a momentary blip stranded the user on "Error loading
+  // payment history" — a real UX regression, and the cause of the flaky
+  // payment-isolation E2E under concurrent-backend load.
   const refetch = useCallback(async () => {
     setError(null);
-    try {
-      // getPaymentHistory uses the authenticated user automatically (REQ-SEC-001)
-      const history = await getPaymentHistory(initialLimit);
-      setPayments(history);
-      setFilteredPayments(history);
-    } catch (err) {
-      setError(
-        err instanceof Error ? err : new Error('Failed to load payment history')
-      );
-    } finally {
-      setLoading(false);
+    const maxAttempts = 3;
+    for (let attempt = 1; attempt <= maxAttempts; attempt++) {
+      try {
+        // getPaymentHistory uses the authenticated user automatically (REQ-SEC-001)
+        const history = await getPaymentHistory(initialLimit);
+        setPayments(history);
+        setFilteredPayments(history);
+        setLoading(false);
+        return;
+      } catch (err) {
+        if (attempt === maxAttempts) {
+          setError(
+            err instanceof Error
+              ? err
+              : new Error('Failed to load payment history')
+          );
+          setLoading(false);
+          return;
+        }
+        // Linear backoff (300ms, 600ms) before the next attempt.
+        await new Promise((r) => setTimeout(r, attempt * 300));
+      }
     }
   }, [initialLimit]);
 
diff --git a/tests/e2e/security/payment-isolation.spec.ts b/tests/e2e/security/payment-isolation.spec.ts
index 91640a1d..6dff4813 100644
--- a/tests/e2e/security/payment-isolation.spec.ts
+++ b/tests/e2e/security/payment-isolation.spec.ts
@@ -141,20 +141,29 @@ test.describe('Payment Isolation E2E - REQ-SEC-001', () => {
       timeout: 10000,
     });
 
-    // Payment history should be scoped to the current user
-    // The "No payment history" heading or payment list should be visible
+    // Payment history should be scoped to the current user: the empty-state
+    // heading OR at least one payment item must be visible. The component
+    // retries a transient fetch error (Realtime/RLS blip during session
+    // hydration under concurrent-backend load) before it surfaces an error,
+    // so poll for a STABLE terminal state rather than asserting on the first
+    // post-loading frame — otherwise we'd race the retry window.
     const noPaymentsHeading = page.getByRole('heading', {
       name: /No payment history/i,
     });
     const paymentList = page.locator('[data-payment-item]');
 
-    // Either empty state or payment list should be visible
-    const hasNoPayments = await noPaymentsHeading
-      .isVisible()
-      .catch(() => false);
-    const hasPayments = (await paymentList.count()) > 0;
-
-    expect(hasNoPayments || hasPayments).toBe(true);
+    await expect
+      .poll(
+        async () => {
+          const hasNoPayments = await noPaymentsHeading
+            .isVisible()
+            .catch(() => false);
+          const hasPayments = (await paymentList.count()) > 0;
+          return hasNoPayments || hasPayments;
+        },
+        { timeout: 15000 }
+      )
+      .toBe(true);
 
     await context.close();
   });