The "disable_polymer" command has been techniclaly depreciated for awhile IIRC. If you don't sign out/clear cache/clear cookies it's remained on the "old layout" though.

As for the huge-black-bar-and-overlapping-the-suggested-videos thing, this is something that literally every already-existing thread on the front page of the subreddit is about (apparently nobody checks to see if anyone else has posted about it and assumes they're the only one) and is happening to people on the new layout as well.

I haven't had the second issue you mention.

I don't think I have the right version for the Media Feature Pack.

I'll continue to use Brave and wait.

dL

Hello Bob,

Why don't you just continue the thumbnails problem in the thread you started about
it last month :

https://support.mozilla.org/en-US/questions/1286260#

Looks that YouTube has discontinued this "disable_polymer=true" feature (I get the same layout with and without the parameter) and that it is no longer possible to revert to the old layout.

• https://www.google.com/search?q=youtube+%22disable_polymer%3Dtrue%22&newwindow=1&biw=1059&bih=645&tbs=cdr%3A1%2Ccd_min%3A1%2F1%2F2020%2Ccd_max%3A

Apart from maybe getting back to your original thread;   would you
please take a look at   these search results .....