You have to click on the button behind the mouse wheel :)

so it doesn't do that for me. it's relatively stable.

Also have the problem that the mouse wheel is very loose, the question is whether this is the case with all of them or whether I should send them back.

I also hear an acoustic sound when moving the mouse back and forth in a jerky manner. The left and right clicks of the mouse wheel only give a weak haptic feedback. I think that's normal for this mouse.
I also use the mouse as a gaming mouse for shooters and RPGs, but have had no problems in this respect.
However, the copy & paste (which is left and right click for me) doesn't really work well. But since I rarely need it, it's not a nuisance and I'm still very satisfied with this mouse for the price at the time.

Ok, thanks for your answer. I thought it was strange that the mouse wheel triggers a beat on medium-fast movements, which you can also feel on your hand. In Quake Champions, I can feel the mouse wheel hitting left and right with every movement. But it's not enough to trigger the button, you need your finger. It feels like a montage model. I think this is strange for a gaming mouse that is pretty much designed for shooters.
I'll test the mouse for a week. Maybe I'll get used to it. It also has to be said that I've been using a g700 (later s) for almost 7 years now.

It's also sensitive for me, but that's more subjective. I do not find it disturbing