Greasy Fork is available in English.
Hover a thumbnail on youtube.com and click an icon at the right: "Not interested" and "Don't recommend channel"
< Opinie na YT: not interested in one click
Works for me. Maybe there's a particular setting in that other script that breaks mine so it'd be helpful if you could try finding it.
i found a conflict with https://greasyfork.org/scripts/381682