I have a reliable Wifi network at home. My wifi calling feature intermittently comes on and off for various calls. Is there a way that I can use my home Wifi network as the primary and the Verizon cellular network as a backup? Currently it is reversed where a phone call will connect to the Verizon Cellular network and switch to Wifi. The problem is switching to wifi is inconsistent and you never know when it will switch over. I would like for the call to connect and if wifi is available it automatically switches over to wifi