data source credentials issues and unable to remove files data flow

Hi rachelb123 ,
Thanks for reaching out Microsoft Fabric Community Foum.

The best and most reliable fix is to first remove anything in your dataflow or report that is still using the old Web connection, then refresh the workspace, and finally delete and add the source again with new credentials. The reason this works is because the system won’t let you delete a data source if it is still being used anywhere. By opening the dataflow and temporarily removing or disabling the queries that depend on that Web link, you break that link so Fabric no longer considers it active. Once you save and refresh, the old connection becomes free, and you should now see the option to delete it in Manage Connections & Gateways. After that, you can recreate the connection cleanly using your own login. 
Thank you.