So the last ad-pocalypse made me install ublock origin, and it's worked a treat. Until 30 minutes ago.
So to keep ad's off youtube videos, use ANYTHING but Google Chrome, to be fair, you're a numpty if you use Chrome.
I prefer Firefox and ublock origin.
Click on ublock Origin, click settings (the 3 gears icon) and click/disable uBlock filters - Quick Fix.
Save and try again, it should be fine

──────────────────◉──────────────────
I◄◄⠀▐▐ ⠀►►I ───○ 02:05 / 04:10 ᴴᴰ ⚙ ❐ ⥂
Autism is a neuro-developmental condition characterised
by difficulties in social interaction and communication,
as well as restricted and repetitive behaviours or interests.
Life on the Spectrum