A lot of users have encountered this USB timeout issue when flashing their AGX Orin, but the root cause varies case by case, and there’s no single universal solution to this issue. Can you try different USB cables, USB ports, or in case you have another Ubuntu PC? Also, Ubuntu 18.04 seems to be more stable than Ubuntu 20.04 empirically.
If all of the above methods do no work, give these posts a try: