Power fluctuating heavily with low cadence

Hi Zwifters!

I started Zwifting about a month ago (with a Flux s) and recently started with the FTP builder plan which is mainly on ERG mode.

Especially during the intervals where I need to slow down cadence (say 70) with a power of ~95. The power output is fluctuating heavily.

Every 1 out of 3 seconds the power shown on the screen drops to 40-50 w, whilst for the other 2 seconds the power is on the right average (90-100w) resulting in the screen constantly telling me I should increase by power… But I don’t see any option in doing that except for increasing my cadence? Resulting in the spin slower, more power spiral.

Is there something I am doing wrong? Or is this a bug in the system?

For other intervals I don’t seem to have this problem (eg higher cadence with lower power or higher cadence and higher power).

Can someone help me out? Missing stars because of this is not so motivating :wink:

What bike are you riding with what drivetrain?

If it’s a typical 2x, shift to the small front chainring, and a mid-cassette cog in the rear that gives a reasonably straight chain-line when in erg-mode.