how roaming in USA
I traveled in Vermont, New Hampshire, Massachusetts last week.
I have 2 phones with new sim card (with lighting) and old sim card.
Both of them work data.
The phone with new sim card connected to T-Mobile and cannot get call or text.
The phone with old sim card connected to AT&T and can get call or text.
Do you have a Androids or iPhones
Both AT&T and T-Mobile should work for data, regardless of what Sim card you have.
my phones all work with data.
AT&T is data only unless you have a new SIM card that now works VoLTE. Some iPhone 13 users already are able to use VoLTE.
so far I think all phone support Volte function, but no all carrier support it example Fizz0
No calls or texts possible.
As of July 2022, only the LTE data network will be available in the United States. You will not be able to make or receive calls and text messages.2
"The phone with new sim card connected to T-Mobile and cannot get call or text"
This is strange. T-Mobile has 2G network for calls. My phone (Samsung A52 5G) has a new SIM card, and can connect to T-Mobile 2G for calls and text. For Data, I have to switch to 4G LTE with T-Mobile.
"The phone old sim card connected to AT&T and can get call or text."
May be right, but AT&T no longer has 2G networks. Probably you were lucky to get an AT&T 3G network. That would explain why you were able to make phone calls over AT&T0
what we can do is that push Fizz to Volte.0
VoLTE is not yet active on Fizz's networks. We will have to wait another while for an announcement.1
In the meantime, maybe you can still make phone calls using T-Mobile's 2G network.
See an outline of how to get along without VoLTE in the USA.0