Hello!
I’m using a ZED Box Orin NX. I created a new user, set a password and gave the administrator privileges to it using the next chain of commands:
sudo useradd -m <username>
sudo passwd <username>
sudo usermod -aG sudo <username>
Then I logged out from default “user” and tried to access the new user, but the screen will go black for a couple of seconds and return to the log in screen. I searched for similar problems on forums but found no answer.