I haven't had any real issues. I have a Wi-Fi calling drop at times, but I suspect a router issue now then the phone. I have not had any LTE signal issues though
Works beautifully for me, although I'm in a dead zone at home. Once I get to a good signal area, it's perfect. Phone also seems to need a STRONG WiFi signal for WiFi calling to work. I think I'm going have to consider a WiFi extender for the house.