Dataflow Workspace lineage keeps old Data source in diagram view

Hi All,

In Dataflow, When I change Data source for queries from Dev Data source to Test Data source, it starts showing both datasources in Workspace lineage for it. I checked connections to be sure that all queries are pointing to Test Data source. I didn't find any way in UI to remove old data source connection and it will always be required to open Dataflow and confirm all queries are pointing to right Data source. 

Has anyone else seen same behavior and have any workarounds? 

Thanks for inputs!