Anyway to get H910 to support T-mobile Wifi calling

[wantpizza]

I have an unlocked and rooted H910. It is my backup phone and I want to get it to work with a T-mobile mvno sim for wifi calling.

Calls and data work with the sim and the wifi calling toggle is there - but when I switch it on it spins and spins for a bit and then says failed.

I tried 10r stock and Alpha-Omega and they both do the same fail when the toggle is switched on.

I would download another ROM but am I chasing something that just will never work? Or is there a app or service that I can delete that ATT is checking for ATT sim before enabling Wifi calling?

Any tips are appreciated.
Thanks

 

[wantpizza]

Not sure if it matters to anyone - but I couldn't find an answer to this. I tried freezing a handful of ATT apps with Titanium Backup. I probably could have wrestled with that a little longer but I gave up. I now have an ATT MVNO sim and it all works fine. So I can confirm that the LG V20 works with wifi calling and VOLTE calling without much issue. (I did have to ask the provider to enable WiFi calling on their end - they made me confirm my 911 emergency address but then it just worked 10 mins later with a reboot)

So - if someone figures this out I am still interested in the answer!

Thanks for looking.