Just got back from vacation this morning and jumped on zwift for a quick spin. When it was locating my devices my powermeter wasn’t awake and under speed cadence I was able to select my trainer (Kurt kinetic). I assume at this point zwift was calculating virtual power and not using my powermeter. What I noticed, is that zwift was showing 50-60 extra watts compared to what my garmin was showing for my powermeter. I even stopped 20 mins into the ride and calibrated my powermeter but the difference was still the same. Is there going to be some way to address the calibration of dumb trainers when using a speed cadence sensor? I liked the extra power I was getting (best time by far on zwift kom) but I know this isn’t real (and won’t be posting to strava) and will make sure only to use my powermeter in the future.
One other note on today’s ride. I saw a few riders going in circles and off the course in certain locations. Never seen this before. The most riders ever were on today (full list +20 that weren’t showing) and don’t know if this was causing issues.