My phone is redmi note 8 pro.
My office building has a t-mobile transmitter inside which cause my phone to automaticly select network as T-mobile, despite having the option "Automatically select network" disabled. I have a sim card from virgin mobile and as a result I cannot use mobile internet...
After several hours of testing, I came to the conclusion that there must be some configuration data be missing for VoWiFi on T-Mobile Austria.
mi 9T Pro
MIUI 11.0.5 (xiaomi.eu)
VoLTE works(! even though no icon is displayed)
VoWiFi does not work with my T-Mobile AT SIM-card, but works with an...