diff --git a/apps/readest-app/src/app/library/components/ReadingProgress.tsx b/apps/readest-app/src/app/library/components/ReadingProgress.tsx
index ad4dc70c..fa53c53b 100644
--- a/apps/readest-app/src/app/library/components/ReadingProgress.tsx
+++ b/apps/readest-app/src/app/library/components/ReadingProgress.tsx
@@ -21,7 +21,7 @@ const ReadingProgress: React.FC<ReadingProgressProps> = memo(
   ({ book }) => {
     const progressPercentage = useMemo(() => getProgressPercentage(book), [book]);
 
-    if (progressPercentage === null) {
+    if (progressPercentage === null || Number.isNaN(progressPercentage)) {
       return null;
     }
 
diff --git a/apps/readest-app/src/app/reader/hooks/useProgressAutoSave.ts b/apps/readest-app/src/app/reader/hooks/useProgressAutoSave.ts
index d401236c..edb6f381 100644
--- a/apps/readest-app/src/app/reader/hooks/useProgressAutoSave.ts
+++ b/apps/readest-app/src/app/reader/hooks/useProgressAutoSave.ts
@@ -13,10 +13,12 @@ export const useProgressAutoSave = (bookKey: string) => {
 
   // eslint-disable-next-line react-hooks/exhaustive-deps
   const saveBookConfig = useCallback(
-    throttle(async () => {
-      const config = getConfig(bookKey)!;
-      const settings = useSettingsStore.getState().settings;
-      await saveConfig(envConfig, bookKey, config, settings);
+    throttle(() => {
+      setTimeout(async () => {
+        const config = getConfig(bookKey)!;
+        const settings = useSettingsStore.getState().settings;
+        await saveConfig(envConfig, bookKey, config, settings);
+      }, 5000);
     }, 10000),
     [],
   );
diff --git a/apps/readest-app/src/hooks/useSync.ts b/apps/readest-app/src/hooks/useSync.ts
index 7d822cfa..d9156ea6 100644
--- a/apps/readest-app/src/hooks/useSync.ts
+++ b/apps/readest-app/src/hooks/useSync.ts
@@ -117,18 +117,16 @@ export function useSync(bookKey?: string) {
           if (!bookId) {
             settings.lastSyncedAtConfigs = maxTime;
             setSettings(settings);
-          } else if (bookKey && config) {
-            config.lastSyncedAtConfig = maxTime;
-            setConfig(bookKey, config);
+          } else if (bookKey) {
+            setConfig(bookKey, { lastSyncedAtConfig: maxTime });
           }
           break;
         case 'notes':
           if (!bookId) {
             settings.lastSyncedAtNotes = maxTime;
             setSettings(settings);
-          } else if (bookKey && config) {
-            config.lastSyncedAtNotes = maxTime;
-            setConfig(bookKey, config);
+          } else if (bookKey) {
+            setConfig(bookKey, { lastSyncedAtNotes: maxTime });
           }
           break;
       }