raceway dmx pass thru

I am helping out a school that has ETC raceways installed and all Color Source fixtures. Not sure if they are Color Source raceways however. The raceways have Stage Pin power outs (5 or 6 - I believe each) and DMX in/out, also I think 5 or 6 each. Each DMX in/out has a pass thru push button switch, switch set in - its blank or black and switch set out - its green.

My concept of what pass thru was, up to this point, it either bypasses that set of dmx jacks and has no output there and runs to the next ones or it sends the dmx thru to the next ones and outputs both.

So I connected a fixture to the first dmx output with pass thru in (black) and the fixture received dmx. I then connected the next one at the next dmx output with that switch also in (black) however no dmx. So I changed the first switch to out (green) and the first fixture as well as the second one had no dmx. So I had to switch all of them to button in (black) and connect both in and out dmx through each fixture or if no fixture there jumper each set of in/out jacks to get the next dmx station to output.

In a nutshell: First one button in (black) dmx out to fixture then fixture out to dmx in then the next dmx out worked if the switch was in (black). And so on.

I expected to be able to dmx a fixture off any output without having to hardwire everything with dmx cables then terminate the end of the line at each raceway.

Not sure if this is factory or wired incorrectly or a choice and wired this way intentionally but now they have to use double dmx cables to daisy chain all fixtures and the individual dmx ports are useless.

Any advice appreciated.