I actually may have this problem eventually in the United States as well, because I’m running a OnePlus Nord N200 with lineage OS, and it does not seem to be capable of voice over LTE while running lineage OS, but will work fine with voice over LTE using the stock ROM, which I refuse to use. Right now I either have to be within range of Wi-Fi or if I place a call my phone falls back to the 2G network in order to place the call and then flips back to 5G when the call ends.
I actually may have this problem eventually in the United States as well, because I’m running a OnePlus Nord N200 with lineage OS, and it does not seem to be capable of voice over LTE while running lineage OS, but will work fine with voice over LTE using the stock ROM, which I refuse to use. Right now I either have to be within range of Wi-Fi or if I place a call my phone falls back to the 2G network in order to place the call and then flips back to 5G when the call ends.