preempt rt buster iso Mesa problem

There do seem to be systems or maybe particular BIOS setups that have issues
with the Buster release.

There are at least three threads on the forum with similar symptoms.
(permission issues)

During installation did the installer at any point ask for a "root" password?
Debian asks for it and it should be left blank, otherwise a lot of stuff will not work properly due to permission issues.

No system did not ask root password during installation.