Request failed due to exceeding the number of allowed attempts for MFA

Question

We have 100s of users connecting to Office365 and our RDS via MFA (AD credentials and a phone number). However, this has stopped working for a few users. Giving this error when trying to call:
Request failed due to exceeding the number of allowed attempts for MFA
No settings have been changed for these users. They were working two days ago. Azure does not show any users blocked. I’ve tried different phones on different networks, none ring. I’ve revoked the users MFA, signed out of all devices. Reset password. Disabled MDA then set to enabled then enforced again. Any ideas? Thanks

Answer 1

The users who are receiving this error can try using a different verification method or signing in using an incognito browser if possible (not sure where they are trying to authenticate).

https://learn.microsoft.com/en-us/azure/active-directory/user-help/multi-factor-authentication-end-user-troubleshoot#to-sign-in-to-your-work-or-school-account-using-another-verification-method

Are you able to check the fiddler trace and backend logs for additional clues? If there are too many MFA registration requests being sent from the client side the MFA requests can get throttled and you may need to bypass MFA for those accounts.