Calls not going through sometimes

I’ll try to make question this as short as I can, but to give context first: I recently, about a month ago, I added my girlfriend to my plan(from xfinity) and got her a new phone along with it but kept her phone number and ported it over. Weirdly, about 50% of the time when I call her it just says “calling” and silence for a few seconds and then straight to voicemail. same with multiple attempts. this is at random locations and isn’t a dead spot of cellular. It happens to her with a few contacts but not all, and same when she tries to call them. Facetime audio always works, so it seems like it’s a cellular issue and not wifi or anything. Texting works fine, and no numbers are/were blocked at any point. Is there an issue due to porting phone lines over? Can this be remedied with resetting some settings or does it need to be a TMobile thing? If anyone could give advice if they have experienced something similar, that would be great. Thanks! 🙏🏻 submitted by /u/Novanh555 [link] [comments]