I'm not sure if this has been covered yet but i found it quite annoying to be restricted to T-Mobile only while in the USA. I fortunately found a fix that at least worked for me. I travel to the USA quite frequently so reliable service is very important.
After watching my phone connect to AT&T while roaming was a good start (for texting and calling), the LTE Logo on my phone would constantly appear and then disappear at a high rate while not connect to AT&T data services. So the last time i was in the US i tried a few different things. Just out random luck i thought hmm lets see what would happen if i turned off 5G on my phone. Instant connection to LTE on the AT&T network. This is a small win for myself as i couldn't get the issue out of my head for whatever reason. Also hopefully a win for members that frequently travel up to Alaska.
Anyways i thought id share my experience with everyone that has been wondering why AT&T has not been working for anyone. I have no idea if this has already been solved or not. I also have no idea if this will work for everyone.
So it seems we can connect to T-Mobile and connect to their 5G network but only the AT&T LTE network which is not really a big deal.
Hope this helps
@RSP93 Well, we do, sort of. But don't ever take what they say at face value. Up until a couple months ago there was no AT&T roaming for a couple years, even though the website still listed them as a roaming partner. I think it's always supposed to have worked, but for whatever reason it didn't for a couple years. Now it is, but it's not without it's issues. TMobile is still more reliable if available, but AT&T is an option as well now.
Yeah AT&T seems to have been made available to us again over the past couple of months. My experience has been that TMobile is still far more reliable. One time I couldn't get phone calls to work on AT&T, and other times I would connect to 5G AT&T (automatically) but data wouldn't work. As soon as I forced my phone down to 4G or onto TMobile, all was good.
For the time being I'd say you should default to T-Mobile if available, and only use AT&T as a backup or in areas with no TMobile coverage, such as Alaska.