This happens to a lot of Nvidia users especially users of newer cards like the RTX series. If for example you are trying to boot and install Linux and you get a black and white grub2 screen instead of a nice graphical welcome installer, you probably suffer from this bug. It is normally followed by the user booting and finding they just have a blank/black screen.
Here is the quick flow of steps to fix it:
If you get a black grub scree........
Debian/Ubuntu vi keyboard problem, up and down arrows do not work and instead make an A (Up), B (Down), C (Right) or D(Left).
The working solution
(you could also add the set nocompatible to /etc/vim/vimrc to make it system wide-will not be applied until reboot I believe):
echo "set nocompatible" > ~/.vimr........