Grub CLI Arrow Keys Don't Work With IPMI SOL
I had exactly the same problem as you but finally I realized we don't need Up arrow and Down arrow to navigate. See the comment at the bottom of the GRUB screen:
Use the ^ and v keys to select which entry is highlighted.
Press enter to boot the selected OS, `e' to edit the commands
before booting or `c' for a command-line. ESC to return
previous menu.
It literally means ^ and V. So by using this, I don't need the arrows.