Jetson AGX Orin not showing in serial connection

The issue can be reproduced very easily.
after upgrade the software, the J40 port is not working , could you help to check it ?

Hi,
The first step is to connect Orin to host PC and let Orin enter recovery mode. Are you able to complete this and see the device in lsusb?

FYI–

I ran into the same problem as the original poster. I upgraded my Orin Rev 0.1 to Rev 1.1 using the quick start instructions and that caused /dev/ttyACM0 to no longer appear on the host machine. I re-flashed according to the accepted answer and that corrected things. My Orin is now sitting at Rev 1.1 and /dev/ttyACM0 shows up as expected on my host machine.