Ok, I have been having this issue with my HTPC.
When playing youtube videos (at any resolution) in chrome the playback is stuttering and a times outta sync with the audio cause its dropping frames. A lot.
Now the funny thing is that this only happens in chrome, playing the exact same video in edge browser/firefox works perfectly.
My HTPC has an intel UHD 600 integrated GPU, quad core celeron clocked at 2Ghz+, coupled with 8GB of RAM and a 250GB M.2 SSD.
Remember, this only happens with chrome.
and here is the same video in edge browser
notice the difference in dropped frames?