Grumpy_Mike:
I would also wire the push button properly, that is with the buttons between input and ground and an external pull up resistor of 1K. With that sort of load using the internal pull up resistor would not have enough immunity against interference.
You seem to be ignoring this advice, why?
Also that data sheet says "VGS @ 10V" and you only have 5V unless you add a transistor to drive it.