Greasy Fork

Is it still working?

Related videos are still mixed with recommendation on the right panel when i am watching a video page.

I don't experience this. Perhaps you could share a screenshot with me and I could take a look at it?

This script is for english youtube. I changed string 'Recommended for you' in code for my language ('Рекомендуемые вам' for russian), and all works.
This can be auto-detected like in similar script (https://greasyfork.org/en/scripts/4246-youtube-hide-recommended-videos/code), but for me manual editing is fine too.