Hello
Thanks for your answers @brent @Staudey @JTCPingas
and yes, just a black screen, the error message and no TTY access as if the keyboard was no longer recognized.
in chroot, I tried different ways and the commands you suggested, brent, but no change.
Then I uninstalled flatpak, and there was no more error, no more black screen, just stuck on the screen with the motherboard manufacturer's logo.
As I had just installed solus, I decided to just reinstall a new solus, downloaded an iso, checked the checksum and reinstalled solus.
I was back on solus and the first thing I did was go to the little graphics driver utility to install the 32bit drivers and then install steam, the driver installation was a bit long so I went to do something else and 10 minutes later I came back to a nice black screen with a message telling me that my session was locked and that I had to open a TTY (giving me the commands to do so) to unlock it, I tried to open a tty, no try as if the keyboard wasn't recognized.
it was Wednesday evening, I'd already lost 4 whole evenings using solus, it was the 3rd time I'd reinstalled it, I humbly confess that I've been rageQuit.
solus is a distribution that has many positive points for my use but obviously it's not love at first sight with my hardware.
Thank you very much for the help you have given me, but the solus adventure ends here for me,,,,,for the moment