Simulink Bus Creation/Model Reference Bug?

For reference, I am using Matlab r2016b.

There seems to be a bug when creating a bus that uses a bus type definition and passing the bus into a model reference. If the bus creator is defined with signal names out of order, selecting signals from the bus works just fine in the top-level model. However, when the bus is passed to a model reference (whos inputs are also set to the bus type), the signal names are seemingly ignored and it decides to use signal order instead, causing the bus values to change. I've attached a simple example where a bus with two signals, "zero" and "one", are set to 0 and 1 respectively.

Is this a bug, or intended behavior?