So, is anyone able to login into the backoffice at all? 
It doesn't look like it. Many people complaining that their 2FA wil not work but not a single case of a member successfully getting in.
I had no problems, and all the members of my team, some had problems, but they quickly decided!
You're advocating the project all the time, so I doubt you can login for real. No one can, since the 2FA doesn't work.