query_function_score["boost_mode"] = "replace"

search/utils/topic.py

@@ -236,6 +236,7 @@ class TopicUtils(object):
                     'operator': 'or',
                     'fields': ["content", "tag_name_list"],
                 }
+                query_function_score["boost_mode"] = "replace"
 
                 query_function_score["query"]["bool"]["should"] = [
                     {'multi_match': multi_match},