Dear Debian community, Thank you for your insights. Unfortunately, the issue has worsened. Today, I observed that upon unplugging the power cable, within one or two seconds, the screen dims (brightness is set to zero), and both the external mouse and keyboard (USB) stop working. Even if I try to use the keyboard or mouse, they do not reactivate. Only the laptop's internal touchpad and keyboard continue to function. When I reconnect the power cable, both the external mouse and keyboard resume working automatically. However, I need to manually adjust the screen brightness. I have not installed the usbguard package. Could there be another underlying cause?
Best regards, -- Marcelo
