it has nothing to do with using the controller, the controller is working fine. the issue your having is that axis events work on tick and they fire even when the input is not pressed. usually you would have the axis value plugged into something thats adds an offset. so when the input is not pressed you would be adding 0 offset, then when input is pressed the axis value becomes 1 and your adding 1 to the offset.
what you can do is to add some flow control to your script and it should work as you intend. for instance try connecting a not equal node to the axis value and make the second value 0, then connect that to a branch node, then the branch true pin to the print string you have. this will make it so the print only gets fired when the button is pressed.