Khurshid Alam - thanks, but those 2 bugs don't seem related.
I managed to isolate a factor:
It recreates only when I reboot with another screen connected (VGA).
I use a laptop, and when I work at my house, It is connected to another main screen.
Rebooting when the VGA is disconnected lets the system run correctly (and then it is possible to connect the screen without recreating the bug).
Khurshid Alam - thanks, but those 2 bugs don't seem related.
I managed to isolate a factor:
It recreates only when I reboot with another screen connected (VGA).
I use a laptop, and when I work at my house, It is connected to another main screen.
Rebooting when the VGA is disconnected lets the system run correctly (and then it is possible to connect the screen without recreating the bug).