[timeon]

This is just anecdote, but sometimes (especially when I'm on slower internet) Safari + AdGuard will have glitch [0] on YouTube. Never happened with Firefox + Ublock Origin.

[0] Unable to press play and showing image with Ad instead.

[c-fe]

I experience the same glitch and i like it because you can just reload the page (cmd-r) and then the video starts so if you're used to it you can skip ads within less than a second and you dont get annoyed by the ad sound/video, just an image.