Silicone/Padding material for membrane

My new controller's dpad is membrane type and press very lightly when I use the dpad. I noticed that dpad up clicks however doesn't register an input; I tested this both wired and wireless on two different pcs. it needs slightly more force to fully register and sometimes I could lighty press into a full click and it still barel registers.

the other dpad buttons work fine and as expected. so my plan is to hopefully just open the thing and add some padding on that one button. If anyone can guide me to useful materials to do so.

Maybe its not that big of an issue/just press harder etc but I like quick tapping quick scrolling through menus with light taps.