We have had SonarQube Cloud working with Okjta SSO for some time now. We have a new user who is trying to log on with SSO and is et with a MFA screen. He does receive the email with the code and enters it but it does not work. In fact this is the only user being met with this screen.
Please have a look at this video and you will see the mfa screen at the 30 second mark. Was this enabled somehow for new users?
We checked your case and we can see that in the meantime more users in your tenant successfully verified their emails. Email verification was indeed introduced mid last year for all SSO users.
There was a temporary issue around the time of your report that might affected your user, which was quickly resolved and should be working without any issues now.