start up SLED

SLED15 (without any Service Pack) is “End of Life”.
https://en.wikipedia.org/wiki/End-of-life_(product)

For security reason you must update to SLED15 SP1.
https://www.suse.com/lifecycle/

You should check every 3 months the support state of your SLED or SLES installation:

Preparation:

[CODE]# su

zypper install zypper-lifecycle-plugin

zypper install lifecycle-data-sle-module-basesystem

zypper install lifecycle-data-sle-module-desktop-applications

zypper install lifecycle-data-sle-module-desktop-productivity[/CODE]

Periodic support check:

[CODE]# su

zypper lifecycle

Product end of support
Codestream: SUSE Linux Enterprise Desktop 15 2028-07-31
SUSE Linux Enterprise Desktop 15 SP1 n/a*

Module end of support
Basesystem Module n/a*
Desktop Applications Module n/a*
Development Tools Module n/a*

Extension end of support
SUSE Linux Enterprise Workstation Extension 15 SP1 n/a*

No packages with end of support different from product.

*) See https://www.suse.com/lifecycle for latest information[/CODE]

Please read carefully chapter 6.1.8 “Showing Life Cycle Information” in SLE Administration Guide:
https://documentation.suse.com/

You should read carefully the SLED15SP1 Upgrade Guide:
https://documentation.suse.com/sled/15-SP1/html/SLED-all/book-sle-upgrade.html
I recommend an online upgrade with zypper (=> chapter 5.5).

You must start a “Xorg” session for a Xorg.0.log file. See SLED15SP1 Gnome User Guide chapter 1.1.1 for more information.
https://documentation.suse.com/sled/15-SP1/html/SLED-all/cha-gnomeuser-start.html#sec-gnome-login

ok, thanks, so I can#t do more here. It happens randomly. After switch off fast boot as Malcolm mentioned the problem seems to be less.

SUSE recommend in SR101276608721 to install xf86-video-intel. You should check your installation for the xf86-video-intel rpm software package:

# rpm -qa |grep -i video-intel xf86-video-intel-2.99.917+git8674.25c9a2fcc-5.19.x86_64

You should open a support request in SCC (Suse Customer Center) for this issue.
https://scc.suse.com/login
=> Support (Headset symbol)

You need at least an active SLED/SLES Standard Subscription to open a support request.
https://www.edv-buchversand.de/suse/url.php?cnt=suse-linux-enterprise-desktop&act=3

As more customer ask for support, as sooner we receive a patch for this bug from SUSE.

Finally: I had to change from WAYLAND driver to X11 X-windows system.
Boomag - the remote system from SUSE can’t handle wayland.
Since I changed the problem seems to be solved.