Update, it doesn’t happen in wired mode, it seems this bug/regression only affects the Lightspeed wireless receiver. Update 2, until this is fixed, the scroll wheel can be fixed using Solaar and these rules: You can gate it behind just the LS receiever if you alternate between wired and wireless, since the wired mode doesn’t have this bug, but it should also not hurt it, so it’s pointless IMHO. Again, I think this should be fixed, it’s very clearly a bug, I’m just not sure where to report ...