Periodically can not connect to TFS - And TFS not in sync



From UiPath Studio 2018.1 I try to connect to our TFS server, via https port 8080
When I set up the TFS server connection I am prompted for credentials, but it does not connect and I am prompted again for credentials. I keep trying, it keeps failing, and suddenly it connects! (??)

… But when I am finally connected, the Project files are NOT really connected to TFS, the green icons are missing, and I cannot check them out for editing. I cannot get latest from server either.

This used to work, but suddenly does not.

Running Windows Server 2016.

Tried uninstalling UiPath, including deleting all uipath program folders, all uipath regedit entries, and all temp files related to UiPath, and rebooting and installing uipath again. To no avail.