My Logitech M705 started acting strange with scrolling. Ideally one scroll of the scroll wheel would produce the same amount of scrolling each time and in the proper direction. Instead it would jump around, bounce back in the wrong direction and be generally unpredictable. The fix that worked for me was updating the firmware on the unifying receiver.
The bonus is that the new firmware fixes a security flaw.
The instructions can be found here on Logitech’s site.
Open the unifying software, go to Advanced, check which version you have, 012… or 024… and grab the corresponding file. Close the Unifying software, run the exe then open the unifying software again and go to Advanced. You should now have a firmware update available by clicking on the Update Firmware button.
It’s hard to tell if this fixes the problem just by resetting the receiver or it was the actual firmware that fixed it. Either way, the scrolling is now fixed.