Thank you, this solved my issue for now...
Bought my Scimitar mouse in November and today when I turned the computer on, the side buttons suddenly didn't work. Tried rebooting the computer, unplug the mouse, plug it in in other USB ports and update iCUE with no success. Going into the device manager and uninstalling the virtual input device solved the issue.
Three year old issue which Corsair still hasn't addressed? I'll most definitely go back to Logitech when it's time to get a new mouse.