diff --git a/vpn/signals.py b/vpn/signals.py
index c6a7241..357eef7 100644
--- a/vpn/signals.py
+++ b/vpn/signals.py
@@ -276,9 +276,14 @@ def certificate_updated(sender, instance, created, **kwargs):
         
         # Schedule sync for each affected server
         for server in servers_to_sync:
-            transaction.on_commit(
-                lambda srv=server: srv.sync_inbounds()
-            )
+            # Only sync if server has sync_inbounds method (Xray servers)
+            real_server = server.get_real_instance()
+            if hasattr(real_server, 'sync_inbounds'):
+                transaction.on_commit(
+                    lambda srv=real_server: srv.sync_inbounds()
+                )
+            else:
+                logger.debug(f"Server {server.name} does not support inbound sync")
 
 
 @receiver(post_save, sender=SubscriptionGroup)
diff --git a/vpn/tasks.py b/vpn/tasks.py
index f0b2acc..3dd6975 100644
--- a/vpn/tasks.py
+++ b/vpn/tasks.py
@@ -297,7 +297,8 @@ def sync_users(self, server_id):
             logger.info(f"Directly synced {added_count} users for Xray server {server.name}")
         else:
             # For non-Xray servers, sync users directly (non-Xray servers should not create tasks)
-            sync_result = server.sync_all_users()
+            real_server = server.get_real_instance()
+            sync_result = real_server.sync_users()
         
         # Check if sync was successful (can be boolean or dict/string)
         sync_successful = bool(sync_result) and (