[dastx]

My biggest annoyance is that it suggests videos I've already watched. Old and new. I totally understand if a recently uploaded video gets suggested several times a day or over a few days, but it suggests videos I've watched years ago, and also months ago. Over and over again.

Their "don't suggest this video" or channel doesn't work for shit either.

[rasz]

inject those two styles into YT website:

    a #video-title { color: red !important;}
    a:visited #video-title { color: black !important;}

[timc3]

That doesn’t help across multiple devices

[simlevesque]

Are you sure the video was registered as seen ? Sometimes on my phone I watch a video and I don't see it in my latest seen videos. It's an issue with Play Service I think.

[bobbean]

I constantly have the same issue. Youtube even shows the video as already watched. I click not interested, then already seen, but another one pops up in it's place. Quite annoying.