There was some discussion of this in one of the admin chats and this seems to be a Hetzner issue. You're post on SDF has the correct metadata. Also compare my post here on feddit.uk (Hetzner) to this one here (Linode).

I just pop catbox.moe screenshot up, my title and link if I care or think it is relevant. That beats the sponsorship garbage that often gets pulled in from YT and the click bait thumbnails too.

I noticed the same thing; I thought it was on my end, hahaha. 

My YouTube link description shows up in Russian; it seems their server that gets the data for links has changed.

A guess: VPNs cause a similar thing to search engine results, where whatever language is the majority shows up in your search results. 

YouTube - youtu.be - Смотрите любимые видео, слушайте любимые песни, загружайте собственные ролики и делитесь ими с друзьями, близкими и целым миром.

Translation:

Watch your favorite videos, listen to your favorite songs, upload your own videos, and share them with friends, family, and the world.