So for a long time now, it seems that after one of the hundreds of thousands of UI changes on YouTube, the player is bugged out in that I can't skip forward to a part that's not loaded yet and have it load/play from there. If I try to do that, it resets the whole loading and puts me back at the beginning of the video. The ONLY solution I've found to this is to click ahead into an un-loaded area, then very quickly change to a different video quality.
The problem is, it's not just Google Chrome. I tried in Firefox, it does the same thing. Couldn't try in IE because apparently Flash wasn't updated in IE and I cba to do stuff for a browser I never touch.
Yes, I tried disabling all extensions, and it still bugs out.