Fix request detail load failures

backend/app/routers/requests.py

@@ -118,6 +118,7 @@ def _cache_get(key: str) -> Optional[Dict[str, Any]]:
 
 def _cache_set(key: str, payload: Dict[str, Any]) -> None:
     _detail_cache[key] = (time.time() + CACHE_TTL_SECONDS, payload)
+    _failed_detail_cache.pop(key, None)
 
 
 def _status_label_with_jellyfin(current_status: Any, jellyfin_available: bool) -> str:
@@ -169,7 +170,6 @@ async def _request_is_available_in_jellyfin(
                 return True
     availability_cache[cache_key] = False
     return False
-    _failed_detail_cache.pop(key, None)
 
 
 def _failure_cache_has(key: str) -> bool:

backend/tests/test_backend_quality.py

@@ -11,6 +11,7 @@ from backend.app.config import settings
 from backend.app.network_security import request_trusts_forwarded_headers, validate_notification_target_url
 from backend.app.routers import auth as auth_router
 from backend.app.routers import portal as portal_router
+from backend.app.routers import requests as requests_router
 from backend.app.routers import status as status_router
 from backend.app.security import PASSWORD_POLICY_MESSAGE, validate_password_policy
 from backend.app.services import password_reset
@@ -117,6 +118,22 @@ class ServiceStatusTests(unittest.IsolatedAsyncioTestCase):
         self.assertIn("credentials", result["message"].lower())
 
 
+class RequestCacheTests(unittest.TestCase):
+    def tearDown(self) -> None:
+        requests_router._detail_cache.clear()
+        requests_router._failed_detail_cache.clear()
+
+    def test_successful_detail_cache_write_clears_prior_failure(self) -> None:
+        key = "request:123"
+        requests_router._failure_cache_set(key)
+        self.assertTrue(requests_router._failure_cache_has(key))
+
+        requests_router._cache_set(key, {"id": 123})
+
+        self.assertFalse(requests_router._failure_cache_has(key))
+        self.assertEqual(requests_router._cache_get(key), {"id": 123})
+
+
 class DatabaseEmailTests(TempDatabaseMixin, unittest.TestCase):
     def test_set_user_email_is_case_insensitive(self) -> None:
         created = db.create_user_if_missing(