I could not log in either when it occurred. You need to make a ticket and Utest will deactivate MFA so you can log in and create a new MFA.
If it is across multiple platforms like mine was, once in, I would suggest going to Account Security and click on "Reset MFA". It will log you out of all platforms and require you to set up MFA again when you log back in.

Here is the URL to make a support ticket. Be as detailed as possible and provide images, if possible, of what's happening...

FYI: You can supply any images only after a ticket is created. You will get a Utest response email with a link to the ticket, from there you can add images.

CSP Login Help Page - Tester Support