You only want one on at any given time... just like the amp channels.
ha! yeah. so, I think I had an 'expectation' of the readout on this unit.
so, I did what you said - lo and behold, it works. what I find confusing is that the channels switch - AND I can switch the FX loop state - but only one light is on at a time. I guess I assumed (my bad) that the lights would show the state of the switch at that current time. given it's a momentary pulse, I guess that's not always possible with that configuration... so once I turned everything on and played through it, proving the FX loop was in and out when I expected it to be, all things are good. it took a little to get my brain around it, but I think I'm good now.
one thing I noticed - when I first started switching the channels, there seemed to be quite a 'POP' as I did it. it seemed the more I played, the less severe the 'POP' sound became. no, not because my ears were bleeding, either...
at any rate, awesome little unit! thankful that I can switch channels on the EVH and presets on my FX unit without having to tap dance to make it happen!