diff --git a/src/cliproxy/management-api-client.ts b/src/cliproxy/management-api-client.ts
index 7fd95ec4..52e89a1b 100644
--- a/src/cliproxy/management-api-client.ts
+++ b/src/cliproxy/management-api-client.ts
@@ -28,7 +28,7 @@ const DEFAULT_HTTPS_PORT = 443;
  * Get effective port based on config and protocol.
  */
 function getEffectivePort(port: number | undefined, protocol: 'http' | 'https'): number {
-  if (port !== undefined && port > 0 && port <= 65535) {
+  if (port !== undefined && Number.isInteger(port) && port > 0 && port <= 65535) {
     return port;
   }
   return protocol === 'https' ? DEFAULT_HTTPS_PORT : DEFAULT_HTTP_PORT;
diff --git a/src/cliproxy/sync/auto-sync-watcher.ts b/src/cliproxy/sync/auto-sync-watcher.ts
index 91046296..48d91139 100644
--- a/src/cliproxy/sync/auto-sync-watcher.ts
+++ b/src/cliproxy/sync/auto-sync-watcher.ts
@@ -152,6 +152,9 @@ export async function stopAutoSyncWatcher(): Promise<void> {
     watcherInstance = null;
     log('Watcher stopped');
   }
+
+  // Reset flag to prevent stale state
+  isSyncing = false;
 }
 
 /**
diff --git a/src/cliproxy/sync/profile-mapper.ts b/src/cliproxy/sync/profile-mapper.ts
index 6929fec3..b3796ef4 100644
--- a/src/cliproxy/sync/profile-mapper.ts
+++ b/src/cliproxy/sync/profile-mapper.ts
@@ -111,7 +111,11 @@ export function mapProfileToClaudeKey(profile: SyncableProfile): ClaudeKey | nul
   const baseUrl = env.ANTHROPIC_BASE_URL;
 
   // Generate prefix from profile name (e.g., "glm" -> "glm-")
-  const prefix = `${sanitizeProfileName(profile.name)}-`;
+  const sanitizedName = sanitizeProfileName(profile.name);
+  if (!sanitizedName || sanitizedName === '') {
+    return null; // Skip profiles with invalid names
+  }
+  const prefix = `${sanitizedName}-`;
 
   // Load model aliases for this profile
   const aliases = getProfileAliases(profile.name);
diff --git a/src/web-server/routes/cliproxy-sync-routes.ts b/src/web-server/routes/cliproxy-sync-routes.ts
index 4b8de047..c0917943 100644
--- a/src/web-server/routes/cliproxy-sync-routes.ts
+++ b/src/web-server/routes/cliproxy-sync-routes.ts
@@ -127,14 +127,17 @@ router.get('/aliases', async (_req: Request, res: Response): Promise<void> => {
 router.post('/aliases', async (req: Request, res: Response): Promise<void> => {
   try {
     const { profile, from, to } = req.body;
+    const trimmedProfile = typeof profile === 'string' ? profile.trim() : '';
+    const trimmedFrom = typeof from === 'string' ? from.trim() : '';
+    const trimmedTo = typeof to === 'string' ? to.trim() : '';
 
-    if (!profile || !from || !to) {
+    if (!trimmedProfile || !trimmedFrom || !trimmedTo) {
       res.status(400).json({ error: 'Missing required fields: profile, from, to' });
       return;
     }
 
-    addProfileAlias(profile, from, to);
-    res.json({ success: true, profile, from, to });
+    addProfileAlias(trimmedProfile, trimmedFrom, trimmedTo);
+    res.json({ success: true, profile: trimmedProfile, from: trimmedFrom, to: trimmedTo });
   } catch (error) {
     res.status(500).json({ error: (error as Error).message });
   }
@@ -148,14 +151,16 @@ router.post('/aliases', async (req: Request, res: Response): Promise<void> => {
 router.delete('/aliases', async (req: Request, res: Response): Promise<void> => {
   try {
     const { profile, from } = req.body;
+    const trimmedProfile = typeof profile === 'string' ? profile.trim() : '';
+    const trimmedFrom = typeof from === 'string' ? from.trim() : '';
 
-    if (!profile || !from) {
+    if (!trimmedProfile || !trimmedFrom) {
       res.status(400).json({ error: 'Missing required fields: profile, from' });
       return;
     }
 
-    const removed = removeProfileAlias(profile, from);
-    res.json({ success: removed, profile, from });
+    const removed = removeProfileAlias(trimmedProfile, trimmedFrom);
+    res.json({ success: removed, profile: trimmedProfile, from: trimmedFrom });
   } catch (error) {
     res.status(500).json({ error: (error as Error).message });
   }
diff --git a/ui/src/hooks/use-cliproxy-sync.ts b/ui/src/hooks/use-cliproxy-sync.ts
index f5ddd517..9611ae38 100644
--- a/ui/src/hooks/use-cliproxy-sync.ts
+++ b/ui/src/hooks/use-cliproxy-sync.ts
@@ -66,8 +66,14 @@ export interface AliasesResponse {
 async function fetchSyncStatus(): Promise<SyncStatus> {
   const response = await fetch('/api/cliproxy/sync/status');
   if (!response.ok) {
-    const error = await response.json();
-    throw new Error(error.message || 'Failed to fetch sync status');
+    let message = 'Failed to fetch sync status';
+    try {
+      const error = await response.json();
+      message = error.error || error.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
   return response.json();
 }
@@ -78,8 +84,14 @@ async function fetchSyncStatus(): Promise<SyncStatus> {
 async function fetchSyncPreview(): Promise<SyncPreview> {
   const response = await fetch('/api/cliproxy/sync/preview');
   if (!response.ok) {
-    const error = await response.json();
-    throw new Error(error.message || 'Failed to fetch sync preview');
+    let message = 'Failed to fetch sync preview';
+    try {
+      const error = await response.json();
+      message = error.error || error.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
   return response.json();
 }
@@ -93,13 +105,18 @@ async function executeSync(): Promise<SyncResult> {
     headers: { 'Content-Type': 'application/json' },
   });
 
-  const data = await response.json();
-
   if (!response.ok) {
-    throw new Error(data.error || 'Sync failed');
+    let message = 'Sync failed';
+    try {
+      const data = await response.json();
+      message = data.error || data.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
 
-  return data;
+  return response.json();
 }
 
 /**
@@ -108,8 +125,14 @@ async function executeSync(): Promise<SyncResult> {
 async function fetchAliases(): Promise<AliasesResponse> {
   const response = await fetch('/api/cliproxy/sync/aliases');
   if (!response.ok) {
-    const error = await response.json();
-    throw new Error(error.message || 'Failed to fetch aliases');
+    let message = 'Failed to fetch aliases';
+    try {
+      const error = await response.json();
+      message = error.error || error.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
   return response.json();
 }
@@ -129,8 +152,14 @@ async function addAlias(params: {
   });
 
   if (!response.ok) {
-    const error = await response.json();
-    throw new Error(error.error || 'Failed to add alias');
+    let message = 'Failed to add alias';
+    try {
+      const error = await response.json();
+      message = error.error || error.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
 
   return response.json();
@@ -150,8 +179,14 @@ async function removeAlias(params: {
   });
 
   if (!response.ok) {
-    const error = await response.json();
-    throw new Error(error.error || 'Failed to remove alias');
+    let message = 'Failed to remove alias';
+    try {
+      const error = await response.json();
+      message = error.error || error.message || message;
+    } catch {
+      // Non-JSON response (e.g., 502 Bad Gateway)
+    }
+    throw new Error(message);
   }
 
   return response.json();