Hi 1712127445,
Are you using the devkit or custom board for AGX Orin?
Please refer to the following thread and apply the patch.
Close or hide UEFI menu - #3 by KevinFFF
Please reflash the board instead of just updating bootloader partition.
$ sudo ./flash.sh jetson-agx-orin-devkit mmcblk0p1
Do you hit the flash issue after you apply the UEFI image built from r35.4.1-updates
? If so, could you try to build UEFI image from r35.4.1
?