I just wanted to share my installation success since several people are having issues with installing the thermostat on a system with multiple zones. I had 4-wires going from each of my thermostats to an Aprilaire zone controller (W,G,R,Y), and then 6 wires going from the controller to the furnace ( the other 2 are for 24v power). Each zone needs its own thermostat as the Wyze won’t control multiple zones on its own, but you can mix and match brands.
Since I did not have a C wire at the thermostat, I needed to use the adapter. The app told me to unplug wires at the furnace, but due to the multi zone controller I learned that the best way was to unplug the wires as they came into the controller from each thermostat, and plug into the adapter. For the C wire connection, there was two wires coming from the furnace to the controller for 24v connection. I pulled the C wire away from the other wires on the adapter so it would reach to the other side of my zone controller, then I just connected it with one of the 24v wires (don’t disconnect the wire). The first wire I tried didn’t work, but the second one did and everything works as designed. Hope this helps.