Using just the supposed discrete On and Off you might get results that make them seem correct. To really test them you need to use other functions as well (as you would in real use).

I don't know enough firmware details of the device to be sure which sequence will prove the supported discrete codes wrong, but I have a good guess:

1) Turn it on with the "discrete On" signal.
2) Use some other function.
3) Try the "discrete On" again. I think it will toggle the device off, because it isn't really a discrete On.