修复

app/services/api/v1/issues/list_service.rb

@@ -17,7 +17,7 @@ class Api::V1::Issues::ListService < ApplicationService
     @participant_category = params[:participant_category] || 'all'
     @keyword = params[:keyword]
     @author_id = params[:author_id]
-    @issue_tag_ids = params[:issue_tag_ids].split(",")
+    @issue_tag_ids = params[:issue_tag_ids].present? ? params[:issue_tag_ids].split(",") : []
     @milestone_id = params[:milestone_id]
     @assigner_id = params[:assigner_id]
     @status_id = params[:status_id]