Trying to duplex 4 pages in a PDF on to 2 sheets. 1st 2 sides should print paper from the bypass tray; the 2nd 2 sides from autoselect. I have managed to get the first side from the bypass tray but it's not duplexing. The next 3 sides are duplexing but us

I'm trying to duplex a 4 page PDF on to 2 sheets. 1st 2 sides should duplex on paper from the bypass tray; the 2nd 2 sides should duplex from autoselect (regular copier paper).  I have managed to get the first side from the bypass tray but it's not duplexing. The next 3 sides are duplexing but using 2 more sheets. Does anyone know how to help me? Janet

Mac user