Favero Assioma MX-2 erratic power numbers

I got some new Favero Assioma MX-2 powermeter pedals couple months ago.

I train by power numbers and display the power targets on my Garmin 840 as seen in the video.

In the beginning everything worked fine and the power numbers went smoothly up and down relative to my input.

However during my last training sessions I noticed that the power numbers on the screen seem to be somewhat erratic and constantly jump up and down by 20-30 watts or more (please see video attached).

This makes training in the given power zones somewhat difficult for me as the power jumps seem so high and unpredictable.

I already checked for calibration and firmware updates. Also I cleaned and reinstalled the pedals.

Did somebody run into the same problem with these pedals? Is there a fix for this?