I just got this “bug” again, second time. It is really annoying to get an empty box for the effort. Losing a booster and a bottle of karma.
To my observation, I completed it with someone ahead of me. Not sure if there is a bug to the chest that while in the same instance, if the chest looted by other player first, then you will loot an empty box.
As for the “touching the box at the finishing end and got port to LA”, do not jump onto the edge of the box and slide down. You will take damage and die, resulting you to port to LA. Instead, aim and jump into the void of the box.