diff --git a/api/core/app/apps/advanced_chat/generate_task_pipeline.py b/api/core/app/apps/advanced_chat/generate_task_pipeline.py
index 85b00a98fd..a760934020 100644
--- a/api/core/app/apps/advanced_chat/generate_task_pipeline.py
+++ b/api/core/app/apps/advanced_chat/generate_task_pipeline.py
@@ -172,6 +172,14 @@ class AdvancedChatAppGenerateTaskPipeline(BasedGenerateTaskPipeline, WorkflowCyc
                 break
             elif isinstance(event, QueueWorkflowStartedEvent):
                 workflow_run = self._handle_workflow_start()
+
+                self._message = db.session.query(Message).filter(Message.id == self._message.id).first()
+                self._message.workflow_run_id = workflow_run.id
+
+                db.session.commit()
+                db.session.refresh(self._message)
+                db.session.close()
+
                 yield self._workflow_start_to_stream_response(
                     task_id=self._application_generate_entity.task_id,
                     workflow_run=workflow_run
@@ -276,7 +284,6 @@ class AdvancedChatAppGenerateTaskPipeline(BasedGenerateTaskPipeline, WorkflowCyc
 
         self._message.answer = self._task_state.answer
         self._message.provider_response_latency = time.perf_counter() - self._start_at
-        self._message.workflow_run_id = self._task_state.workflow_run_id
 
         if self._task_state.metadata and self._task_state.metadata.get('usage'):
             usage = LLMUsage(**self._task_state.metadata['usage'])
diff --git a/api/core/workflow/nodes/variable_assigner/variable_assigner_node.py b/api/core/workflow/nodes/variable_assigner/variable_assigner_node.py
index 660011a082..ef6b399aab 100644
--- a/api/core/workflow/nodes/variable_assigner/variable_assigner_node.py
+++ b/api/core/workflow/nodes/variable_assigner/variable_assigner_node.py
@@ -17,12 +17,7 @@ class VariableAssignerNode(BaseNode):
         outputs = {}
         for variable in node_data.variables:
             value = variable_pool.get_variable_value(variable)
-            if value:
-                variable_pool.append_variable(
-                    node_id=self.node_id,
-                    variable_key_list=variable,
-                    value=value
-                )
+            if value is not None:
                 outputs = {
                     "output": value
                 }