Thumbnails Aren't Updating for Featured & Playlists

[Creepimus]

Even though the smaller thumbnail for "Sequences" updates correctly, the larger thumbnail for "Featured" & "Playlists" doesn't for some reason.
   

Notice how there's something there in the bottom-right for "Sequences" which isn't there at all for "Featured" & "Playlists".
                                                                                                                                                                 

This is what it's basically supposed to look like in the thumbnail for "Featured" & "Playlists", by the way.
   

I really hope that this is an actual bug & not something along the lines of having a predetermined thumbnail once it has been set on "Featured" &/or "Playlists" for the first time because if that's the case, that'll just be unnecessarily annoying & it should still be changed either way.