Iphone 13 Pro Max Thought I'd share my experience thus far with the latest iPhone. I've been very happy with the iPhone X Max other than making the mistake of only getting 64K in memory - it's worked flawlessly and was a huge upgrade from my previous 7 Plus, I just kept getting low on memory due to the many apps, photos and videos I take. I rationalized upgrading because my old 7 plus, given to my wife was starting to get too far behind in version. Thus I preordered an unlocked phone directly from Apple (I use T-Mobile as the carrier).
The phone arrived on Monday so I did a full encrypted backup (if you're going to update from a backup the encrypted mode saves most of your account settings and 3rd Party passwords) and started using the teleport app (you hold your old phone near the new and follow the prompts). Teleport worked flawlessly and everything was setup and working. One thing I noticed during setup, for some reason the phone thinks I have two lines - one for data and another for phone/primary, even though they are the same number.
It was the next day, when trying to respond to a text that I found something remiss - I kept getting "not delivered" errors and then when the same person tried to call me it went directly into voicemail - that's when I discovered that calls weren't working (note that slack, messenger and other apps continued to work).
I used my wife's phone to contact T-Mobile support - they were fantastic - much kudos to "Arvin your tech buddy" for walking me through various screens to troubleshoot. It immediately became apparent that my phone was configured differently that those he'd troubleshot previously - some of the menu options were in secondary settings screens. In any case, he was able to get my call options working - took about an hour, however the texts are still wonky. I can receive texts but can't reply or send. Also as part of this, Apple iMessage is disabled.
Arvin escalated my issue to Tier 2/3 and I'm supposed to get an update when it's been fixed - yesterday received a call from him to confirm everything is working - nope still not working. He told me that I'd be notified once it was working by the team doing the troubleshooting.
Anyway, that's been my experience thus far. I'm thinking I may have been sent some international version of the phone or something - I've heard that Apple is way back-ordered so I guess I'll just have to deal with it.