Check this out:
https://forums.developer.nvidia.com/t/cannot-use-usb-devices/343707/10
All of that is for setting up a thumb drive or other external drive someone expects to use on different Jetsons.
The really big question is how did you configure? You should start with an unconfigured kernel, and choose an empty location for all temporary output. That is what a lot of the above URL is about, although it is way more detailed than just basic instructions. Keep in mind that if you build the kernel Image itself, and if that Image has any change in integrated features (a change to an “=y”), then most likely you’ve invalidated all modules, including those in the initrd. The install procedure for that is far different than the simple file copy of building a module intended to load into the original kernel.
If you have already replaced your kernel with one which did not exactly match the earlier kernel’s integrated features, then you probably have to start over.
Note that it is almost always safer to add a boot entry for a new kernel with a new name and other details, and leave the old kernel in place. If the new one fails, then you have a backup boot plan. If the system fails now, then you might need to flash again (you could clone first, or if it is on an SD card, simply fix it on a host PC by putting the original kernel back in place).
Also, booting from SD card on a dev kit Orin Nano is quite different than booting from an NVMe. The boot chain is somewhat custom, and so you can’t just interchange bootable devices the same way you could on a computer which has an actual hardware BIOS.
Let me know what the situation is.