Bug#902928: Cannot bring the grub menu up with Shift key along with GRUB_TIMEOUT_STYLE=hidden with GRUB_TIMEOUT=0

[Yuri D'Elia]

Package: grub-efi-amd64
Version: 2.02+dfsg1-4
Severity: important

I was using grub-pc until recently, where I migrated to grub-efi-amd64.
It's the same hardware (lenovo yoga x1).

My grub configuration is unchanged, and consists of:

GRUB_TIMEOUT=0
GRUB_TIMEOUT_STYLE=hidden

I was used to hold shift during boot to bring the grub menu up during
boot, which worked flawlessy.

With grub-efi-amd64 it doesn't work anymore.