Fix regression from #2683

netbox/dcim/signals.py

@@ -37,7 +37,7 @@ def update_connected_endpoints(instance, **kwargs):
 
     # Check if this Cable has formed a complete path. If so, update both endpoints.
     endpoint_a, endpoint_b, path_status = instance.get_path_endpoints()
-    if hasattr(endpoint_a, 'connected_endpoint') and hasattr(endpoint_b, 'connected_endpoint'):
+    if endpoint_a is not None and endpoint_b is not None:
         endpoint_a.connected_endpoint = endpoint_b
         endpoint_a.connection_status = path_status
         endpoint_a.save()