That is about the same for me. It was Public Mobile service was great, until two days ago and it's pretty much gone. ( A few random moments it works, but generally, not working).
I did all of that. When I changed to LTE from 4 G it now works. However, there is no guarantee it will stay. My husband's phone is also with PM, and his phone has an identical issue. I did all you suggested on his phone and it 'didn't' fix his iss...
I had your support yesterday. Data was not showing up on my phone and I couldn't access it. The service person got me up and running. This morning, my phone has 'no data available. I need support, please.