Both monitors show completely black screens when turning on the system

I use Windows 11, Home Edition and, as far as I know, I’m current with all updates.

When turning on the system this morning, both screens remained totally black. One screen (the secondary one), flashes small squares with “HDMI” or “Analog” in the upper corners for short periods. Both screens are connected to the PC with HDMI cables. The mouse cursor also displays continuously on that screen.

The system worked perfectly when I turned it off last night.

I tried rebooting into the Windows Recovery Environment, using the three successive turning on and off method. Since I could see nothing on the screens, I used the start-up sound to key turning off. After several attempts, I never got to the WRE to then enter Safe Mode to diagnose and repair the issue.

I also checked all connections on the screens and the PC itself, with no apparent or obvious issues.

I’m at a loss as to how to proceed or do next that a least allows me to get into a diagnostic mode. Any help is greatly appreciated.