After last snapshot no more VT available on raspberry pi 400

I did an update today via zypper dup and tried to reboot after but the system locked with a strange message about kvm.
I did a hard reboot and the system started but after selecting tumbleweed on the grub menu nothing was displayed. After1 or 2 minutes I received the graphical login screen and could login.
I tried to go the vt1 via alt-ctrl-f1 but the screen remains the same and the VT is not displayed. Also all actions are locked and the cursor is not more visible.
If I do alt-ctrl-f7 then the cursor come back and the graphical session is again active.
I tried also all other VT but had the same problem

in journalctl I found this error

Jul 19 18:06:36 rasp kernel: detected fb_set_par error, error code: -16

If I do alt-ctl-f1 and type root + enter and then the root password if see in journalctl

Jul 19 18:38:45 rasp login[7968]: pam_unix(mogin:session): session opened for user root(uid=0) by LOGIN (uid=0)
Jul 19 18:38:45 rasp login[7968]: ROOT LOGIN ON tty1

but the VT tty1 screen is not displayed but via ps-ef | grep tty if have a line

root       9456  7968   0 18:38 tty1    00:00:00 -bash

Any hint?
Regards
Philippe

Solved: I forced reinstall of the kernel and after reboot the problem is solved.

Regards
Philippe