I have a notebook with Fedora 34 Workstation Official Edition, an external monitor and no UPS. The primary monitor is the external one. Turning on the computer, Fedora starts the login on the notebook monitor. But after that, there was the power outage, the external monitor was black. I have to reset the primary back to notebook. Is it possible for Fedora to switch automatically back to the notebook monitor ?
Have you tried disconnect the external monitor before booting?