Youtube videos are glitchy, pixelaze or etc

Hello guys,
From few months I’ve got problem with videos on Youtube (doesn’t matter from quality) , some times in Facebook also. I don’t know how to describe it, but it start to pixelize like on the top of the screen and some times on the middle. Like it try to skip some of the frames. The video is going smoothly not like on the screenshot. Before 2-3 months everything was fine. From where is the problem ,and how can I fix it. Thank you! Video : https://youtu.be/pnxoEInW2G0

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This site is not for Support, which it says rather clearly when you create your account. You can refer to https://community.ubuntu.com/t/finding-help/712 for a list of support channels, though I know you already know of them, as I’ve seen this same request elsewhere already.

Please use Ubuntu Support channels, and not cross-post the same request in multiple places, especially in non-Support Community sites.