anyone experience wifi calling auto disable issue? it takes a while (few mins) to switch to wifi calling after iphone is connected wifi, and sometimes the wifi calling will no longer show in the status bar, need to turn off/on wifi calling to enable it back. my house has very bad reception, only first floor windows side can get signal.

My iphone 6s plus wifi calling is not stable either, occasionally it will drop calls, and sometimes wifi calling turn off and I got no reception at all (mobile signal inside my house is very weak == almost no signal, that's why I need wifi calling), my wifi coverage is always full inside my house.