When I get a Text from my partner it shows up as a message from me instead of them

My last Iphone (Gen 1 SE) was a hand me down from my partner and I never changed the contact card thing to reflect that it was now mine.

I recently upgraded to a new IPhone 15 Pro and did a restore from my old phone. I decided to finally update the contact card with my name, phone number and picture.

His contact info disappeared from my contact list after I made those changes, so I added him again as a new contact.

However, now when I get Texts from my him, they still come up in messages under my name and picture despite the changes

how do I rectify this?

Thanks!