Lack of power in ERG mode


When I run “force” workouts, for example 10 blocks in zone 2 (for me 200W) at low RPM (55 rpm), the 4 first blocks are ok, the next 3 blocks are almost ok, but for the 3 last one, the power is lowering at around 180 W and there is nothing to do, even by manually increasing the expected power, for example to 225W via the Companion application.

If I pedal harder I’ll just increase my rpm but not reach the 200W targeted power…

This is not a new problem; I’ve encountered it at every session of this type for at least a month.

I’m running the latest version of Zwift (on Apple TV), on the up to date Zwift Hub. And that doesn’t change anything to this problem.

Thank you in advance for your answers.