I have a rpi 3 with berryboot running openelec, and retropie. ATXRaspi will shut the pi off, but will not turn back on, so I still have to unplug, and replugin to turn on with the ATXRaspi button.
What power supply?
What type of switch? Latching/momentary? Wiring closeup photo would help a lot to eliminate any assumptions.
ATXRaspi is OS independent, as long as the BOOTOK and SHUTDOWN signals are asserted as expected. I provide a shutdown script that does all that at startup. How this works is all explained in detail and in a video on the ATXRaspi guide (https://lowpowerlab.com/atxraspi).