Can/us data plan not working in US

[Lorriam1]

I'm unable to use my phone for anything in the States. I'm currently registered on the Tmobile network with full bars 5g but there is no functionality at all. I've tried creating a new apn with the values suggested by public mobile but no matter what I do my phone always chooses the default apn. The values of both are more or less the same. I have a Canada/US 50g plan on an esim. My phone is samsung s23. Thanks for any help you can give me.

[Lorriam1]

Okay, so I feel kinda stupid. I requested a plan change bfore I left home to kick in on the next month's payment.  I assumed that my plan had changed, but upon double checking my subscription, I see it had NOT changed! So I changed my plan to a Canada US one a few minutes ago and low and behold...it's working!  Thank you to everyone who made suggestions to help!

[PM_5G]

Please post what ends up working for you!

My Samsung S22 Ultra 5G Worked Just South of the BC Border in Bellingham and Pt. Roberts
Automatic Network Operator and 5G worked!(Manual Network Selection did not!)
Public shows as Carrier with an R on Signal Meter(Roaming)

What I Did/Checked:
Make sure you have selected Public's SIM or eSIM
S22 is VoLTE Capable (For Making Calls) 

FIRST Reboot Your Phone if and when phone plan changes! (Public Mobile Updates your phone's settings)

Data Roaming MUST Be Enabled(Leave it Enabled - PM is Prepaid so there are never Roaming Fees)
Network Operators - Auto
Network Mode can be switched to 5G/LTE or LTE(4G)

Android Settings Location for these settings:
Settings / Connections / Mobile Networks / Data Roaming
Settings/Connections/Network Operators - Select Automatically
Settings/Connections/Mobile Networks/Network Mode - Select 5G or LTE(4G)

Manually Selecting T-Mobile or AT&T DID NOT work for me(Got Network Not Found Error)

Some have had luck manually selecting T-Mobile or AT&T
AT&T 5G as Network Mode has not worked apparently only LTE.

[softech]

@Lorriam1 

don't use the 5G, use only 4G or LTE

and if that still does not work, still have the network set to 4G and try manually connect to AT&T network