probably it is the mouse wheel

Hi Sabatola, maybe the scrolling function in the Logitech software is incorrect? Otherwise it's probably a warranty case.

Hi!

So the mouse wheel is "fixed", am I understanding you correctly? Even with a bit of force, it can no longer be turned?

I can only imagine 2 scenarios that could apply here:
Either something got into this "shaft" from the outside, which I find rather unlikely.
Or a component has broken off and is now blocking the barrel...
I see more potential here, since the mouse wheel has two functions and you have to engage it every time you change from free running to stepped running. I could imagine that one of the teeth would have broken off...
However, I would take the part to a branch!