BugSir009 I have the exact same issue myself that the 2FA token stopped working.
I was able to reset/remove it myself.
I have updated my password for my MX account as well, just in case.
But when I try to recreate a new 2FA token, it gives a error, and the secret ID field is empty.
I am on "Version 7.3.1.8600"
Trying to generate a new 2FA code by logging into the mymaxthon link on a different browser yields the same results. where it cannot generate a 2FA token/QR code