Check Settings > Messages > Send & Receive. Make sure that your phone number is checked there.For some reason switching to Public Mobile removed my number from the iMessage setting, whereas I never had to fix iMessage when switching before. Can I ask...
I just had to deal with this. Password was wrong even though it was automatically made and saved. Resetting the password didn't work. App had a blank screen and the website constantly refused my login.I had to make a support ticket and someone got ba...