Youtube ads in videos has just this moment started again. It was ok earlier this morning.
I have Brave v1.71.123
Not sure if there is anything I can try. I realise they’re always trying to stop browsers getting round them! Trouble is I seem to get so many ads that I give up watching the videos!
If you look for old movies and soundtracks at YouTube, you will find some that do NOT include in-video ads. Find one and bookmark it.
After clearing cache and cookies, and then quitting Brave Browser . . . start up Brave Browser and go to one of those videos that you found and bookmarked.
I suspect, that may get you in the door, and from there, go to one of the videos where you encountered trouble.