Xperia III, IV, or V What is the best phone for Sailfish OS with VoLTE

VoLTE is working fine here (KPN, the Netherlands), but I’m also having odd issues on 5G: My phone often stays connected to 4G despite 5G being available; and when “Prefer 5G” is selected, call recording often doesn’t work from what I’ve tried.

All is fine as long as “Prefer 4G” is selected for me!