ads not working properly

[blackm3out]

I've been having this issue for the last week or so. I don't have premium so every once in a while Ill get an add to watch a video, except there's no ad to watch. It just sits there for 30 seconds. The same with random video ads. It'll say "the next 30 minutes are ad free thanks to the following sponsor" and then it will just go back to playing my music.