Thanks for getting in touch, 5Gissues.
It sounds like you're having trouble receiving SMS shortcakes after porting your number to a new carrier network. We can help.
SMS features are not supported by Apple, instead they are set up and managed through your cellular provider.
If you don't receive a text message response using different short codes, this could mean that your wireless plan doesn't support short code messaging, something isn't provisioned, or some type of restriction is in place. In this case, you'll need to call your wireless phone provider to troubleshoot further.
Hope that helps!
Take care.