eSIM woes

Anyone know where to find the Android (and PMOS eventually) settings for eSIM? Running Lineage OS without gapps for now, in a MAJOR metropolitan area with plenty of cell coverage from both T-Mobile & ATT. Basic cell data seems to work without doing anything special, but calls on cheogram are spotty at best - pretty much unusable. general web browsing seems to work OK and I even see 5G in my phone's status bar, but calling on Signal app fails as well. I even started seeing"Network failure" errors. Everything works perfectly if I switch back to my SIM card from a T-Mobile MNVO.

seems like this eSIM requires some config to work well with my local towers, but I can't find any documentation online. What am I missing?