Hi @kaspar,
Thank you very much for sending the diagnostic logs.
Based on the logs, you have a Virtual Desktop (from https://www.vrdesktop.net/) installed in your primary machine.
This software seems to have incompatibility issue with spacedesk.
We were able to reproduce the same Display Off issue after installing the Virtual Desktop then reboot.
Please try this workaround steps to make it work with spacedesk:
– open device manager in your primary machine (just run devmgmt.msc)
– go to Display adapters and right-click Enable device the “Virtual Desktop Monitor”
– open spacedesk Driver Console then switch the spacedesk SERVER OFF-ON
If the steps above did not help, the only option is to uninstall the Virtual Desktop app then reboot your primary machine.