I have the same problem. My username doesn't have any dots in though. It consists of letters and numbers only.

I'm using my old work account to post this reply, which luckily still works.

I don't really want to choose a new username for my main account, as doing so will obviously lose all history and ability to reply to previous posted threads which isn't ideal.

Does anyone know if this is being looked at, or how to get it fixed?