I get neither with uBO. Seems that different people have different experiences, either due to outdated uBO filters or differences in YT behavior.
I don't get any ads whatsoever on YouTube with uBO. What I do get is about a 20% chance of something screwing up in the ad blocking process for prerolls and getting the grey "there was an error" screen instead of a video. I just hit reload and the video starts playing.
Slightly annoying, but I don't utilize auto play, so I don't have to worry about it stopping my playlist or passive watching.