Switched to Xfinity mobile and my iPhone is now not receiving any SMS messages

I just switched from ATT to Xfinity mobile, and I have an iPhone 16. Prior to the switch my SMS messaging was working fine.  Since switching, I can receive iMessages, but not SMS messages.  This is incredibly problematic because I am not receiving any of the two factor authentication code texts to log in.  I have turned my phone off and back on, reset my network setting, and checked all my message settings to confirm SMS messages is turned on.