Screen blanking while working with LibreOffice

Hi,

For about a week, I have been noticing a strange issue with LibreOffice (using libreoffice-kf5, in fedora-38-xfce based qube). While working on a stylesheet in Calc, suddenly the screen may go blank for 2-3 seconds and then it recovers. This can happen more than once while working on the document.

Watching dom0’s journal, I always see:

[ 6291.508457] dom0 sudo[32343]: PAM unable to dlopen(/usr/lib64/security/pam_sss.so): /usr/lib64/security/pam_sss.so: cannot open shared object file: No such file or directory
[ 6291.508744] dom0 sudo[32343]: PAM adding faulty module: /usr/lib64/security/pam_sss.so

In some of the cases also:

[ 6471.017481] dom0 kernel: i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

Has anyone else noticed that?
Any possible fix?