Same problem, recently moved to TMo.
Two OP7's on our plan, and a Pixel 3a. The 3a works fine, the OP7's do not.
The OP7's don't work with the TMo VVM app, either, so it sure *seems* like it's something server/provisioning-side, since all the voice->text work would be on their side...
I've been through two tiers of techs, at TMo, so far, tons of stupid "reboot, phone-cache-clear, app-cache-clear, ...".
They did say they sent a test-provision, but really no one seems to be able to actually trace/debug stuff, you'd think they'd have some basic tracing tools (I say this as someone who'd worked for quite some years, in s/w dev).
I've disabled/enabled WiFi calling (per the comment above), across a couple of uninstall/reinstall of the TMo VVM app, forced APN re-provisioning, etc.
I await a call back, on Monday, but I really don't think they're going to have any answer.
It's a bit bizarre, I bet they'll say I can't expect consistency with the TMo-VVM app, without a T-Mobile branded device, hmm (it makes no sense, from a s/w abstraction side anyway) ;-]
Logging is next, I suppose, if their support just throws up their hands...
Last edited: May 23, 2020
