Another Welcome AboaRd, Lucas!
I started to answer you earlier, but I don't know how things work with the Envoy. I have a Davis Console and it has an LCD screen that is used to 'tell' it you have additional transmitters (such as the wireless anemometer, which I also have). I can only assume that, since the Envoy doesn't have its own screen, that settings like this are done on the computer, probably with WeatherLink?
Unfortunately, you probably only have the version of the app that runs on Windows. On the other hand, I would think that you have already set up the Envoy to receive the signals from the anemometer, so I'm not sure why its info is not being 'seen' by WeatherCat.
It's been more than a year since I started up my station and WC, so I have no memory of doing anything in the app to have it 'learn' anything about the wireless transmitter that I bought some time later. I'm pretty sure all I had to do was make sure that the Console was 'listening' to the new, wireless transmitter (page 10-11 in the Console manual).
Upon re-reading your post, I see that you actually have a Console. I suspect that it is not near your computer and the Envoy is what is connected to the Mac.
? 1. Is that correct?
? 2. Does the Console indicate wind data?
? 3. Does the Envoy in a "Re-Transmit" mode?
--- OR ---
? 4. Does the Console "Re-Transmit" to the Envoy?