I use both the wahoo cadence and speed sensors over Bluetooth. My wattage is fine but my rpm is way off compared to the same tracking in wahoo fitness app. If my rpm is showing at 100 in Wahoo, it’s only registering at 60 in Zwift. Am I missing something? Thanks!
Please tell us more about your setup. Are you using the Wahoo app and the Zwift app at the same time? Bluetooth devices are a 1-to-1 set up, so if your sensor is connected to the Wahoo app via BT and can’t also be connected to Zwift at the same time.
Also tell us what do you use to measure wattage. Most power meters built into trainers can determine cadence as well. They do it by detecting reduction of torque applied to pedals when pedals are at 12 oi’clock / 6 o’clock position. It does not matter what gear you are in, the electronics can pick up cadence just the same. A separate cadence sensor on the bicycle is not necessary, in most cases. Same applies to speed, by the way - avatar speed in Zwift is calculated from power, weight, size of the rider, and terrain slope.
Thanks so much for the feedback!
I do not use the Wahoo app and Zwift in tandem because of the one-one connection.
My trainer is old school (Cyleops Power) so my external sensor is required. Although this whole experience has got me thinking about upgrading for next season! 
