Error when trying to load the system from a microSD on Jetson Nano (on another Jetson Nano board it loaded without issues)

Not enough information to really say much about this. Are all units involved SD card models? Are any eMMC models? I suspect SD card, but some people want to boot eMMC models with SD card.

FYI, part of the boot chain must be in the eMMC of the eMMC models, and thus if booting from another device on that eMMC model, the module would require flashing (the boot content and rootfs need to be compatible, and since eMMC models split that content between QSPI memory and the boot device, it is possible for an SD card boot to work on one but fail on the other).

In the case of this being an SD card model, then perhaps there are revision issues between carrier boards.