I've tried a blank program and forcing outputs, both expansions work.
I've tried a very simple program that turns on an output, both expansions work.
In my main program, the first expansion operational, but the second expansion still does not function. I've even placed a line of code that simply turns on an output to the second board, and still nothing turns on, although the online monitioring screen shows the output as being on. Really scratching my head on this one