I remember trying a home made cardboard one that worked pretty well. Make it just big enough for him to stop messing with it.
I found this link with some suggestions while trying to find a picture or video https://pangovet.com/pet-lifestyle/cats/diy-cat-cone-collars/ they make a paper plate one which is the same idea. Might be a good place for inspiration.
It typically was because people kept posting their youtube or stream spam. I never 100% understood it either because what if it was an actual relavant video, then why not allow it?