I have loaded many different Operating systems and while I can get ATT / Cricket to work well ,I have had no luck what so ever getting any OS to recognize the T-mobile Sim. Tried loading atinout, modem manger and other software to no avail. I am trying to avoid using the modem update software since I don't want to risk trashing the modem. Heck, flashing my Bio makes me nervous. Has anyone found a way around my problem?
Check my post
https://forum.pine64.org/showthread.php?...8#pid85368 for VoLTE settings / modem AT commands, it might help.
I don't have a SIM for an operator that has VoLTE enabled but you should be able to check for yourself (presuming the SIM works on VoLTE with another phone).
There is a "Commercial-TMO_VoLTE" profile in the modem so that would presumably be used automatically if VoLTE is enabled - you can also set it manually yourself.
Hope that helps.
There's also a thread for confirmed 4G VoLTE working here
https://forum.pine64.org/showthread.php?tid=12560 if you get it to work. That should help, too.
Pinephone v1.2 UBports CE. Adelaide, Australia using Amaysim SIM (Optus network, VoLTE enabled) with Mobian SD card. VoLTE working also with Felix / Vodafone AU and Aldimobile / Telstra AU.
Manjaro Plasma Mobile on EMMC.