Dual boot Odyssey X86 after firmware upgrade SD-BS-CJ41G-300-101-F

Updated bios firmware on Odyssey X86 and can no longer get grub menu to display. Have the Odyssey with emmc and windows, and nmve ssd with debian installed. Tried to sudo update-grub2, checked grub.cfg, and tried install of other distros - still no grub menu. Grub errors when trying to install on mmcblk0,1,2,3,or 4 (the emmc). Grub did install and work fine on nmve0 (the ssd sata) prior to firmware (F) update. I could go back to firmware SD-BS-CJ41G-300-101-K, but that version lacked stability and crashs after 10 to 15 minutes with no solution there. Firmware (F) gives better stability but still crashes. Haven’t used windows long enough to comment on stability and emmc. Anybody having these problems?