macOS suddenly exhibits weird mouse acceleration after idling
I've had similar issues with a Logitech MX2 & Logi Options.
My bet is the Logi controller that 'forgets' what it's doing.
Tests would include:-
- uninstalling their drivers & see if the same happens without;
- test a different mouse;
- see if your G-series can be used fully with something like SteerMouse or USB Overdrive.