I finished the PWR MUX , when pcie is used then it gets the 12v and 3.3v , that means the usb 5 to 3.3v and the 5v from usb cant be on at the same time , this power mux design wich was a headache because of many states and sometimes wierd graphs passes the 5v from usb to system and the 3.3v buck (from usb 5v) output to the system normally . When 12v is detected it disconnects these power lanes and activates an 12v to 5v buck aswell as the 3.3v from pcie is used then !