Unable to use FaceTime on my iPhone 15 Pro Max

I can use face time fine on all my devices EXCEPT my phone. Despite being logged in to my correct appleID on my phone, when I try to FaceTime on my phone, and only on my phone, i get the error message WITH THE WRONG email with no punctuation mynameoutlookcom - ie no @, no . (even though I am logged in to the correct email Apple ID which is myname@outlook.com). Message says: your apple account “mynameoutlookcom” is not eligible to use FaceTime. Use this phone number with an iPhone to make calls from this number, or add an email address to your account (which of course there is both a phone number AND then email Apple ID that I am ALREADY logged in to correctly. Then there’s a button that says add email but when you click it nothing happens. This has been bugging me since I got my 15 2 years ago. Never had it with my previous phone. Yes I am logged in correctly. I have tried going on appleID.com and my email is correct there - this only affects my phone.

[Re-Titled by Moderator]