"Boot from hard disk" does not proceed

[abulhol]

I randomly have the issue that after restoring, the FOG boot menu does not proceed at all.
Next to the entry “Boot from hard disk”, there is normally a counter from 3 to 1, and then it boots.
But in this case, there is no counter, nothing happens.
If I press Return, the boots process continues normally.
If reboot the machine once more, the “Boot from hard disk” also works again as expected.
What could be causing this?

I am running the latest FOG version.