@johnym30 Can't see anything wrong with the sketch that causes the 2 outputs toggle at the same time. However, I have 2 remarks:

1. Don't you need to set the pins to output before you set them low?
2. You are not updating your gateway when you toggle the output with the switch.

@johnym30 Can you post your sketch?

You can also set

#pragma once

as the fist line of a header file to prevent multiple inclusions.

If you create a new version, could you connect the other 2 5V and GND holes next to D6 so these can easily be used as power output?