Most are with no change in riding position. The one drop the last time I stood @ MM46:34 coresponds with standing, but seems odd that it went to 0. The ‘dip’ at the second standing section @ MM40:33 seem s plausible to just be transitioning. All other drops or quick dips happened with no actual change in position or pedal speed.
I’d be inclined to say it’s some form of interference but the cadence never drops.(i.e. MM 38.43) Power goes to zero but cadence stays steady.