So this started coming up today. On every video. I can (so far) click the "x" and remove it to watch (still see 2 ads before the video, and one after 4 minutes - ruins music on YT), but did click the "Report issue" only for the dialogue box not to work.
I found a link to a that said 11% use adblock. Thats not a lot.Maaayyyybe there is a problem with the amount of ads youtube forces down our throats for even short videos. 🤷♂️
There's a few options
Newpipe, uses it's own extractor, also can act as a player for SoundCloud and Peertube, there's also a fork with SponsorBlock: https://newpipe.net/
Libretube, uses the Piped api, generally seen as the one with the best UI: https://github.com/libre-tube/LibreTube
Clipious, uses the Invidious api: https://github.com/lamarios/clipious
Could also watch videos in a browser from an Invidious or Piped instance I guess
And while I'm at it I'll also mention there's a client option on desktop too, Freetube: https://freetubeapp.io/