If you were to copy an image directly, then you are correct. The reason I mention this:
3.) format with FAT32
In some cases JetPack or SDKM creates an image by first unpacking files into a file system. The image which is written uses the same file system where the files were unpacked at. If the image was created where any point in the chain FAT32 was used, then your image inherited FAT32 and won’t work. Did you verify the image created was really ext4 at every step?
If you can loopback mount the “Linux_for_Tegra/bootloader/system.img.raw”, and then look at the permissions of “usr/bin/sudo”, then you should see “-rwsr-xr-x 1 root root”. If “s” is missing, then you have FAT32 somewhere in the chain of building the image.