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.