Thank you for posting your issue on Microsoft Q&A.
I understand that you have enforced per user MFA but while signing in MFA is not triggered.
- Check whether any Conditional Access Policy is applied and if applied disabled Per user MFA.
- Try to Revoke Multifactor Authentication Sessions.
- Try to sign in private window, and check if issue has been resolved.
Hope this helps. Do let us know if you have any further queries.
If this answers your query, do click `Accept Answer`
and `Yes`
.
Thanks,
B. Siri Chandana.