tried the APN, hd voice, calling, messages and even video calling work direct from the dialer. I don't mind using Google messages in order to get RCS but I do prefer samsung messages. The other annoying part is that when I turn on my phone or take it off airplane mode I get the "simcard is not from verizon wireless" notification.
the phone does work with T-Mobile fine. I have calls, video, and messaging. but I want to use Samsung default app for RCS and not Google messeges. from the research I have done sm-n976v is not able to be flashed with a different firmware. guess I'll have to sell and get a tmobile sm-976u model.
I actually am familiar with bring your own device. as my phone is an unlocked version sm-n975u1 and I have a b.y.o.d. sim card if in. was the phone unlocked when you purchased it? and where did you buy it from?
most times you have to check with the networks b.y.o.d. program to see if the device is compatible before putting in their sim by inputting the i.m.e.i. if it isn't compatible then another sim won't work correctly. I had this problem with a previous phone. could call and all but some features wouldn't work as it wasn't compatible with their services.