[2022] e-mail field on the login screen limits max character number to 16

I don't see a 16 character limit on the email address field, and it doesn't matter whether it's a fresh login or a hotseat login. Are you using any kind of intermediary tools like an onscreen keyboard? Is there anything unusual about how the previous player is logging out?

It doesn't seem to "just happen", even if last login was your address.  Creator mode is interesting though. Are you interacting with any text boxes just before signing out?  What is your game language set to?