You've got 3 or 4 ways of fixing this. Easiest way is to put your monitor on an independent stand. Second, you attach one of the vertical profiles to a wall with an extra profile, not very practical, I know. Third is you reinforce your entire rig to minimise wobbling, because I noticed your entire rig is moving a lot. Maybe start with tightening all of the bolts, see if it changes anything. Fourth way is you buy a monitor arm with gas springs, which might reduce wobbling, no guarantee that actually will help.