RPM doesn't register on Zwift calibration page

MPH doesn’t register when I try to calibrate in Zwift. Consequently, my speed and mileage are off compared to my Garmin. I’ve not had luck getting a response from Zwift help.
I’m using my computer, not the app. I have a Wahoo Kickr Snap. I’m using Bluetooth. Pairing with Zwift is fine and I see the wrench to click for calibration. I’ve disconnected, reconnected the traininer, uninstalled and reinstalled the app… nothing works

Thanks for any help on this!