Zwift Not recognizing Garmin Speed / Cadence Correctly

Normally I ride with a Quarq powermeter, but I am currently revamping that bike, so I am using my back up bike which has a Garmin Speed / Cadence sensor. I haven’t had any troubles using this set up in the past, but today as I was soft pedaling at 13 mph Zwift was showing 2 mph. My laptop with the Ant+ dongle was about 2 feet away from the sensor during this time.

I logged out and singed back in, but the problem was the same. I have tried everything I can think of to fix the problem.

Has anyone else had this issue?

Were you going up any hill in Zwift at the time?

Your speed in Zwift has nothing to do with your Bike Speed senor but is a measurement of your power against the slope of the current road you are on in the game. At a guess you were showing 2mph as the power reading was low.