Laptop shows some YouTube videos pixelated, graphics card defective?

Hello with some YouTube videos, the picture is very pixelated to me (see picture) and sometimes it also happens that the laptop is completely spinning and the whole screen is pixelated. Is the graphics card defective? I ask for help

Is the graphics card defective?

Unlikely.

The rest of the desktop is still displayed correctly. What does not work correctly here is the "overlay" playback of the videos.

Go to the settings of your browser and switch off the "hardware acceleration".