I am testing the ad blocking on YouTube when I am logged out and/or logged into a non-premium account to see how the ad blocking works
video playback is flawless until it gets to the ad, and then the video playback basically freezes, and goes to a black screen, and then it resumes several seconds later.
for now, its relatively unimportant because I have YouTube premium, however, a big reason, is because of ads, and if I can cancel it, would be a nice savings, so I would like to report this bug to get the youTube video ad blocking working flawlessly 
I expected it to be blocking ads in the background or something (aka = uninterrupted video playback as if I had YouTube premium)
the latest (just installed the other day)
Catalina (10.15)
18