I just tried that, and the same thing is happening. I copied my old files somewhere else to test with empty default directories (archive, backup, etc). I then tried to create a new server, but again no name in the dropdown or dashboard. It does show the side tabs for server settings, backup and restore, and logging. In the Server Status tab and under the Delete Server header the paths read like this:
Delete Archives: undefined/archive/testing
Delete Restore Points: undefined/backup/testing
Delete Live Server Files: undefined/servers/testing
so I think that may show part of the problem.
EDIT: I tried some more troubleshooting and followed the steps I found here: Possible change of location(path) for the server files - #2 by JayMontana36.
After numerous restarts and moving files and directories around nothing has changed. It might be important to note that the new base directory location is part of a cifs share.