Resistance Drop During Free Ride of Structured Workout

Hi - I’m completing the 4wk FTP Booster training course, props to whoever made it, it’s great (it’s taking me ~6 weeks but that’s on me…).

In some of the structured workouts, I use erg mode, there is a free ride section that has no preset power. When I do this It starts out at a hard resistance, but then it just gets easier and easier. Then I raise it a gear, it increases the resistance, but then it keeps dropping, and that process repeats. Any suggestion to make the free ride an actual free ride?

I’m running Zwift on my laptop, a wahoo kikr core trainer, and having power read from my quark power meter.

Thanks for the help!