Microsoft Outlook Verification notification issue

-- I also checked the recent activity log on my Microsoft account, and it only recorded my sign-ins.

Microsoft nerfed the Recent Activity page. It's worthless.

https://learn.microsoft.com/en-us/answers/questions/4727900/activity-missing-from-view-my-sign-in-activity

-- Is someone trying to get into my email?

Yes.

-- Any ideas would be great

Separate Login Only and Email Only Aliases

https://learn.microsoft.com/en-us/answers/questions/5725931/how-to-stop-multiple-2fa-requests-that-are-not-min

If all the Bad Guys have is your Email Only alias then they get "This username has been turned-off for sign in" at the very first step of the logon process and can not continue.

Don't forget to change your default Send From in Outlook to your Email Only alias. (It defaults to your Primary Alias). For New Outlook: View -> View Settings -> Mail -> Sync email -> Set default From address.