In years gone by the container was meant to stay with the aircraft as there are only a small number of them. Now on the AKL-LAX-AKL run it is sometimes offloaded in LAX for freight uplift on the way back. You will probably find most of the stock is now in LAX.
If they are being fitted and being turned around to not give crew access, either the ramp in AKL or LAX may not know which way it is to be fitted. Someone should ask a question of management about this. If it is being turned around on purpose on orders from management, then get the union involved.