Hi, @DavidW! You mean you don't have an employee named "Menu.LoggedAsShort?!"
This isn't a bug as much as a blip related to Saturday's release. It's working now for me, so I'm hoping the same is true for you.
I've communicated with the team and this should be resolved today or tomorrow, if not already. (The functionality is working - you ARE successfully proxied in as the person. It's just the labeling of the person's name that's not displaying correctly.)