Many people have commented on Sliders for volume control. Just because the slider is ON in the menu doesn't mean it will control volume. The sliders can be used for many different purposes, depending on how they are set. They also need to be targetted to the right Zone. If I want slider one only to operate zone one, then it needs to be switched off for zones 2,3 and 4. Then Slider 2 for zone 2, means it needs to be switched off for 1,3 and 4. I know it all seems a little confusing at first but I have only had my PX5s a week and gigged with it last night. No problems at all, including setups using drums, Bass, arps, pianos and strings. Al independently controllable on volume sliders. There is a great video clip on youtube that simply shows you how to assign sliders and tones for volume layer adjustment.
None of us could run before we could walk and this instrument is no exception. I am loving it and have done some amazing setups in just a few days. I am confident that it is just a matter of getting your head around the architecture. Once you have done that, the world is your oyster..........Enjoy.....