Question [Q] Wrong carrier name

When I flash p.a. rom the carrier name is always wrong. I have the correct apn. I try to select the carrier manually but it doesn't work. I'm on AT&T and it says ROAM as the carrier. I'm not actually roaming, it just has the carrier name as ROAM. On cm based roms it shows as AT&T so I know it's not my sim card or location. Any help is greatly appreciated!