Ubuntu 21.10 Broken Boot - Grub 2 Changes Made to Access Bios Infinite Boot no Display (Bricked)
Bios(or UEFI) has nothing to do with grub. Bios always comes first. It(the bios/UEFI) looks (after its own initialization) at the first partition if there is an operating system. This is where grub comes in. I would not mess with with grub and its so called extensions - so you did not brick your PC, but you might've bricked your bootloader. Use the stick you've taken for installing your Ubuntu and fix your grub (without any extensions). This explains how to fix your grub with a live USB - This link is a detailed explanation on how to fix your bootloader with a special boot repair. This has been asked many times in this forum, so I'm not elaborating the steps.