diff --git a/api/core/workflow/nodes/answer/base_stream_processor.py b/api/core/workflow/nodes/answer/base_stream_processor.py
index 6671ff074..09d5464d7 100644
--- a/api/core/workflow/nodes/answer/base_stream_processor.py
+++ b/api/core/workflow/nodes/answer/base_stream_processor.py
@@ -57,7 +57,6 @@ class StreamProcessor(ABC):
 
                     # The branch_identify parameter is added to ensure that
                     # only nodes in the correct logical branch are included.
-                    reachable_node_ids.append(edge.target_node_id)
                     ids = self._fetch_node_ids_in_reachable_branch(edge.target_node_id, run_result.edge_source_handle)
                     reachable_node_ids.extend(ids)
                 else:
@@ -74,6 +73,8 @@ class StreamProcessor(ABC):
                 self._remove_node_ids_in_unreachable_branch(node_id, reachable_node_ids)
 
     def _fetch_node_ids_in_reachable_branch(self, node_id: str, branch_identify: Optional[str] = None) -> list[str]:
+        if node_id not in self.rest_node_ids:
+            self.rest_node_ids.append(node_id)
         node_ids = []
         for edge in self.graph.edge_mapping.get(node_id, []):
             if edge.target_node_id == self.graph.root_node_id: