I agree.
I figured it a while ago but didnt have an account here. The flickering in my case looked like it was switching between default led effect (when there is no app running) and the effects i chose in corsair icue. After pc restart it was always fine.
I tried to close windows by using shift + click (hard shut down) for a few days and the problem didnt occurr even once. Didn`t know there is a feature like in the video you mentioned. It saved me the trouble.
Would be nice if corsair worked on that so we wouldnt need to turn windows features off tho.
Thanks.
