I was told when this happened with ATT a few weeks ago that the account owners phone was fucked and all the sub accounts were good plus business accounts were unexpected.
I lost coverage for 5 hours on my personal ATT phone but I was able to use my work ATT phone to call my wife.
https://m.youtube.com/watch?v=rw2nkoGLhrE&t=185s&pp=ygULbWFkIHR2IGlyYW4%3D