Here is my setup:
Power source: PowerTap P1 pedals connected via ANT+
Wahoo Bolt head unit (displaying 3s power average)
2018 MacBook pro with ANT+ dongle
Displaying 3s avg power in Zwift
I connect to the head unit to access avg watts, laps, NP, IF, and partially to have a second power reading. With this setup, Zwift normally reads 10% higher than the Bolt. I have triple checked that both pedals are connected to Zwift and made sure I’m not seeing a single side readout. I rode a steady state effort for ~90 mins this morning. Zwift read 198 while the Bolt recorded a 179 watt average. Scratching my head here to figure out where the discrepancy is coming from since the pedals should be broadcasting the same readout to both devices.
I can provide both workout files if that helps.