So, I moved over from AT&T to Xfinity Mobile about 8 months ago. Originally, there was a problem porting the number over, but it was resolved in a few days. I've been using my iPhone 8 Plus with voicemail without any issues for 7 months. Then a few weeks ago, people would call and try to leave a voicemail. They would get a message that my AT&T voicemail was not working. AT&T!!! What the heck is going on? I've been in touch with customer service for weeks trying to get this resolved. A new SIM card didn't work. Then they sent me a replacement phone. During the activation process, I was told that the IMEI number was not the correct number for the old phone. I was happy that perhaps this was the issue. I went ahead and activated the new phone, now with the proper IMEI number on Xfinity's end.
Unfortunately, I'm still getting the AT&T voicemail issue. They tried to reset the voicemail again, but that didn't work. I don't know what to do. I need my voicemail.