calls go straight to voicemail

[mlody_me]

Hi,
About a month ago or so, I wanted to try a different phone to see if I like it more. I used a new phone for only a few days but decided to go back to my old phone. Since that event, my phone (iPhone 11 Pro Max) stops ringing after few hours, and the only solution is to either reboot the iPhone or reset the network settings, but then a few hours later, the same issue reoccurs.

I have been to Costco to replace the sim card, to reprovision the phone etc - no resolution. I even reached out to Apple; they didn't find any issues with the phone. Per Apple's advice, I then wiped the phone clean, and it worked for a few days, but the problem is back. At this point, I have no clue what to do. I am angry at Verizon that they can't fix the issue and don't care about their existing customers. If I can't resolve this in a reasonable time frame, I am moving my line and 4 others to ATT as I can't deal with a non-functioning phone and continue to pay for this mediocre service.

Thanks