diff --git a/api/db/services/knowledgebase_service.py b/api/db/services/knowledgebase_service.py
index a8a98cf81..5f506888c 100644
--- a/api/db/services/knowledgebase_service.py
+++ b/api/db/services/knowledgebase_service.py
@@ -411,8 +411,6 @@ class KnowledgebaseService(CommonService):
         ok, _t = TenantService.get_by_id(tenant_id)
         if not ok:
             return False, get_data_error_result(message="Tenant not found.")
-        if kwargs.get("parser_config") and isinstance(kwargs["parser_config"], dict) and not kwargs["parser_config"].get("llm_id"):
-            kwargs["parser_config"]["llm_id"] = _t.llm_id
 
         # Build payload
         kb_id = get_uuid()
@@ -427,6 +425,7 @@ class KnowledgebaseService(CommonService):
 
         # Update parser_config (always override with validated default/merged config)
         payload["parser_config"] = get_parser_config(parser_id, kwargs.get("parser_config"))
+        payload["parser_config"]["llm_id"] = _t.llm_id
 
         return True, payload
 
diff --git a/rag/flow/tokenizer/tokenizer.py b/rag/flow/tokenizer/tokenizer.py
index a13d95c0a..f723e992f 100644
--- a/rag/flow/tokenizer/tokenizer.py
+++ b/rag/flow/tokenizer/tokenizer.py
@@ -105,6 +105,9 @@ class Tokenizer(ProcessBase):
 
     async def _invoke(self, **kwargs):
         try:
+            chunks = kwargs.get("chunks")
+            kwargs["chunks"] = [c for c in chunks if c is not None]
+
             from_upstream = TokenizerFromUpstream.model_validate(kwargs)
         except Exception as e:
             self.set_output("_ERROR", f"Input error: {str(e)}")