Hi. While a Live ISO image debian-live-9.7.0-amd64-gnome.iso with those properties
$ file -b debian-live-9.7.0-amd64-gnome.iso
DOS/MBR boot sector; partition 2 : ID=0xef, start-CHS (0x3ff,254,63), end-CHS (0x3ff,254,63), startsector 1416, 832 sectors
has been written to an external flash drive relying on command dd,
and once media was booted from BIOS, Debian installation steps had to
rely exclusively on the use of arrows in order to be operational, since
the pointer did not respond to invocations; it stayed at its default
position, centred onto the screen.