VoLTE/Wi-Fi calling working on T-Mobile

On T-Mobile, Nokia 7.1 with 10. Wi-Fi calling works but LTE is a totally different story.
With it set to use 4G and VoLTE turned on calls to me go straight to voicemail and when I call others my voice drops out so much they can't understand me.
Only thing that works is to set preference to 3G.