Same issue - Called ATT 800 331-0500 (don’t listen to the bot asking questions - just hit “0” 3 times to get live support) last night working with Level One support for an hour with no success before being transferred to Level 2 - waited 40 minutes for a tech to answer only to be told their system was down and I had to call back. I offered to hold on until his system came back up, but he said that wasn’t possible due to the large number of customers waiting in the queue behind me he had to inform about the system outage. I gave it another shot this morning. Heads up - Level One will have you try the myAT&T app to setup voicemail - press and hold down “1” which calls your voicemail where you are asked to enter your voicemail number (not tel #) - no clue what that is, going to your voicemail icon on the phone app has the option of calling your voicemail as well with same result. When she had exhausted all her attempts, I was transferred to Level 2 support. After 30 minutes on hold, I lucked out with a knowledgeable tech. Somehow visual voicemail is dropped during the upgrade migration and has to be manually activated again. That’s why all the Level One support attempts to set up voicemail failed, because it didn’t exist on my account. After the Level 2 tech entered corrections, she had me go to the voicemail icon on the phone app where instead of “call voicemail” being displayed was the setup voicemail option. I was prompted to create a voicemail password and voila! - all my old voicemails appeared. WaHoo!!
Out of habit, I had performed the iPhone backup and restore on my Mac. I since learned of an automatic set up process to restore a new iPhone from your old iPhone which might be the way to go. If anyone has used that and experienced no issues losing their AT&T visual voicemail, let us know.
In all the articles I read outlining the steps to ensure a smooth upgrade to a new iPhone, I never saw visual voicemail mentioned once. One reason we stay with iPhones is for the secure trouble free and seamless interface with the apps. Getting back my voicemail consumed 3 hrs of valuable AT&T support time on an issue which never should have been dumped in their laps. It should have been caught and resolved by the Apple and AT&T pre-release teams in the weeks leading up to the new iPhones. Until it is fixed - hit “0” three times, ask right away to be transferred to Level 2 - tell them last night after 2 hours of being on hold and working with Level 1, you reached a Level 2 tech only to be told - “the system is down - you have to call back.” (I did ask for a direct Level 2 support 800 number, but was told there wasn’t one). Good luck!
Automatic Setup for iPhone 12
https://www.cultofmac.com/652858/how-to-upgrade-to-the-new-iphone-11-and-iphone-11-pro-the-right-way/