Powermatch issues with Magnus/820

I’m having recurring issues with power control of my Magnus trainer using the CIQ app on a Garmin 820. At the beginning of the ride actual power is way lower than target, and doesn’t seem to respond much to target power increases. For example, last night I began with a 12 minute warm up consisting of six minutes at 120W followed by six minutes at 140W. Avg. power for the first six minutes was 105W (120 target). For the next 3:30 it was 110 W (140 target). There was no particularly discernible increase in resistance when the target moved from 120 to 140. However, at about the 9:30 mark I felt a noticeable increase in resistance and the final 2:30 of the interval averaged 138W (140 target). The remainder of the workout was pretty much spot on, with the exception of the first half of my cool down set, where target power was 140W and avg. power was 157. I checked all the settings at the beginning of the ride - power control and power match were both on and the trainer was selected. Any idea what’s happening here?

I can’t say for sure but it would appear that your powermatch is calibrating. The calibration may change as your trainer warms up or you change gears. The trainer itself may adjust too. Do a longer warmup and maintain the same gear. Do one of our workouts that have alternating power as a warmup. This acts as calibration for powermatch.