I have a first gen Nest Thermostat with a W1 Y1 G and RC. When I attempted to install the Wyze thermostat It said I needed the C-wire adapter. I wired it up per the instructions and I have no power going to the thermostat. I don’t have a control board and instead the wires go to what looks like a small transformer in the air handler.
Have you tried swtching the Red wire from the RC to the Rw on the thermostat? Can you include a photo of the transformer?
Also, when I had installed the adapter I missed the part in the instructions that said to install the G wire in the C terminal at the thermostat, after I moved it, it powered up. Just something else to check.
I realized that after I posted this. I already put my nest back on until after Christmas. I will try it and post an update. Thanks!