Youtube premium A/B test weirdness (oshi no ko)

Hi guys so something weird I noticed about youtube and their enhanced premium experiments. Last week I had enhanced premium availble as an option. I don't use youtube premium so I went with stock 1080p. Quality was kinda degreaded.

This week however the enhanced 1080p was missing but the video quality for 1080p looked considerably better

Any thoughts?

Imgur album

https://imgur.com/a/CYoKIB8

Source video:

【推しの子】STAR☆T☆RAIN/新生B小町【第十一話「アイドル」挿入歌】

https://youtu.be/S-UmqvA7uR8?t=4