This sounds like something missconfigured with your keyboard / button settings. Check if some of your buttons are mapped to the wrong action. Also check the sensitivity seetings of your controler and set a according deadzone.
If you use the experimental version with custom flybywire, also be sure you configured your thottler controler correctly (see instructions on our gitbhub page). You can also try the developer version first (same as the experimental, but without our custom flybywire).