Raspberry Pi (RPI5) keyboard non-functional at boot

The RPI5 has a boot selection in the firmware now, where you hold space down at power on and then can select a device to boot from. The KVM is unable to activate this. secondly when attached a a real USB keyboard and holding space to get into the menu, the KVM is unable to register any key-presses, ie I can’t even hit “1” on the KVM to boot into SD card.

This is a bit a problem as we are using the KVM to rescue remote RPI5s.

Have you tried to disabled the Virtual media function in KVM?
Also please try to change the device identity.