hello tianchi.yu,
you’ll need to re-flash the target in order to update the cfg settings.
you may see developer guide, To clone a Jetson device and flash, which backup your filesystem (i.e. system.img) to reserve your user-space contents. after that, please use the command-line to restore your backup image for flashing the target.
for example, $ sudo ./flash.sh -r jetson-xavier-nx-devkit mmcblk0p1
there’re some discussion threads you may check for reference, i.e. Topic 169760, and Topic 205693.