Wifi calling runs fine for me, though it does depend on your home router playing nice. To explain a little, your phone sets up a vpn with your cell provider, then sends the call over that. The exact networking setting is nat pass through. If your router doesn't play nice, it might cut the connection. Not experienced cut offs myself but I have accidentally broken wifi calling. I disabled some nat pass through settings as "I don't use these vpn protocols". Turns out wifi calling does and that disabled it for me. To avoid messing with router settings, try setting wifi calling to "mobile network prefered". It'll use your mobile data for the call instead of wifi, should be the same quality but might avoid strange issues. If it's already set to that, set it to wifi preferred. All the phones I've had with wifi calling default to mobile network for some reason, making wifi calling not actually use wifi.
