Cadence wrong on DuoTrap...help

I use a Bontrager DuoTrap for speed and cadence. When on Zwift the speed picks up fine but the cadence runs about 30 RPM less than what I’m actually doing. Anybody know how to fix this? Not a big deal on normal rides but if you’re doing a workout that includes cadence changes it’s not helpful.

I have same problem. Did you ever find a solution?