I dont remeber where but i years ago found in internet something about increase buffering videos on yt or something like that and it said to go to about:settings and change something but yea i dont remember what i changed i mean for long time when i close browser with opened video it all the time move back video to old time for example video 1h and i close at 30 min but earlier i closed at 10 min and it will move all the time back to 10 min.It was something about saving video time i extended it to max probably so maybe every one hour or something it will track the time.