Just have received this email after I couldnt log in anymore.
After that I have resetted my password account and it still didnt let me login.
But I was finally able to enter like this:
Login as Root at https://signin.aws.amazon.com/
When asking for 2FA / MFA then click on the bottom "Trouble signing in?"
Then click on Re-sync with AWS Servers
Then put in two 2FA codes after waiting for 30s apprx.
Finally enter again
Done ✅