FaceTime won't go through my new iPhone 15

I transferred from an iPhone 12 to a new iPhone 15. All my facetimes have been completely fine but for some reason when my boyfriend facetimes it doesn’t go through to my new phone, but when I facetime him it goes through fine. All my other facetimes and calls have went through completely fine except when he facetimes?…

[Re-Titled by Moderator]