I expect that all four ports are actually working OK. On the 40X1, Port D is an input-only port, so unlikely to even accept code to toggle the pins as outputs.
However, the PIC16F887 PIC that the 40X1 is built on has four bi-directional ports, so it may be possible to use the SFRs to turn these pins into outputs. I have not tried to do this, so you will be on your own if you want experiment.