This is a continuation of this thread who has been closed, so I cannot add additional posts to it:
Unfortunately, the solution in that thread is only temporary - after a few days/one week, the issue reoccurs and I have to go through the whole rigmarole again. Sometimes, the error: “The anonymous account you’re currently using is unavailable” persists even after reinstalling all updates, so it takes a day (or two) for app lounge to work again.
This is a real pain - I am surprised nobody else has encountered this issue, as I run a bog-standard /e/ installation.
I have managed to reproduce this issue 3 times now, so I know it is an ongoing thing, not just a fluke.