Nothing wrong with the phone. This is the response I got from the support agent at PM:First that all, I want to apologize for the inconvenience you might be experiencing while US roaming, and thank you for understanding the situation of the US 3G Net...
I’ve had similar issues - spending money on Uber due to unavailable data. We should not be wasting time troubleshooting issues. Public Mobile should ensure that they deliver the service or not offer it at all if unable to do so.