Fixed tab recreation logic and improved error handling

src/myfasthtml/core/instances.py

@@ -210,15 +210,24 @@ class InstancesManager:
   
   @staticmethod
   def dynamic_get(session, component_parent: tuple, component: tuple):
-    parent_type, parent_id = component_parent
     component_type, component_id = component
-    
+
+    # 1. Check if component already exists
+    existing = InstancesManager.get(session, component_id, None)
+    if existing is not None:
+      logger.debug(f"Component {component_id} already exists, returning existing instance")
+      return existing
+
+    # 2. Component doesn't exist, create it
+    parent_type, parent_id = component_parent
+
     # parent should always exist
     parent = InstancesManager.get(session, parent_id)
-    
+
     real_component_type = snake_to_pascal(component_type.removeprefix("mf-"))
     component_full_type = f"myfasthtml.controls.{real_component_type}.{real_component_type}"
     cls = get_class(component_full_type)
+    logger.debug(f"Creating new component {component_id} of type {real_component_type}")
     return cls(parent, _id=component_id)
   
   @staticmethod