Garmin Data versus zwift Data in ride

Hi all,

Im using garmin vector 3’s dual sided for power on a mag trainer and im confused with the power numbers quoted in zwift…

If i track my peak power output for any given ride with my Garmin Edge it consistently reports power figures around 100watts higher than zwift at peak power both are set to 3 second averaging so just trying to understand why such a difference…

Anyone else noted similar…