Look for any of Logitech Options / Options+, Razer Synapse, SteelSeries GG, Corsair iCUE, KensingtonWorks, Synaptics/ELAN touchpad suites, “smooth scrolling” utilities, etc, AutoHotkey, PowerToys ,“mouse gesture”, macro tools. Any could be causing it, many could have per app profile for mouse options. I would hear about it from many people and scrolling code has not been touched in years, and I need a way to reproduce the issue.