Microsoft Account Team email fails fraud detection checks. How do I check if it is genuine?

Hi I recently had a string of wierd things happen and am not sure whether my account has been compromised or whether it is the security checks overfunctioning.

I replied to an email from a trusted source, but was told that my reply failed some kind of junk mail test and wouldn't send. It said to rephrase the message, so I did and also changed the title and it sent fine. Then my smartphone came up with a message that sign in had failed as my password had been changed.

So I went to my account settings on the pc and was shown a message "it looks like someone else has been using your account" and to enter the number sent to my security option, which I did and changed the password, and all seemed fine.

It then said to remove any alternative security options that seemed suspicious. Everything was normal, but I removed the last one I had used just in case.

Changed password and logged in all fine.  I'm guessing the security check required me to re-set my password.

When I went to reply to an email, it said invalid alias - because that was the one I had removed. So I went to re-instate it.

But when I received the verification link email there is a warning on that "Be Careful! This sender has failed our verification checks".

This is an expected email from microsoft account team to re-instate my alias.

Are the security checks just going bonkers today or is this a problem? And how can I re-instate my alias?

Thank you.