Hello Pierre!

I narrowed down the issue.

So I tried logging in as i3-wm session and streamed/played videos, the
video+desktop stuttering did not occur. This is the case with both of
linux-libre versions 4.9 and 5.3.

But when I login as gnome session and try to stream/play videos, the
video+desktop stuttering occurs. This is the case with both of linux-
libre version 4.9 and 5.3.

So the problem seems to be with gnome. What should I do?

Regards,
RG.