Hello everybody, thanks to the french Solus community on Telegram, I think I have solved my problem.
That « glitches » are not « glitches » BUT tearing.
To fix the problem, I had to do the next thing :
- I opened a terminal
sudo gedit /etc/X11/xorg.conf.d/20-intel.conf
- On gedit, I wrote the next thing :
Then I rebooted the computer.
But truth is I got again tearing on a multimedia software very famous… Gnome MPV. And I really don't know this time how to fix the problem.