Pressing Esc key doesn’t return to boot menu

[Paul Menzel]

Using Ubuntu 16.04 LTS with GNU GRUB version 2.0.2~beta2-36ubuntu3.8, pressing Esc during “GRUB phase” enters the GRUB menu. Sometimes, I accidentally press it twice (or it’s recognized as twice on the Dell XPS 13 9360), I am dropped into the GRUB command line. Pressing ESC there, I am unable to leave the GRUB command line, and instead of returning to the menu, it looks like it’s recognizing a newline, that means, a new line is shown, as if return is pressed.