Raiju Quartz Tournament Square Button Problem

Hi, I very recently (within the last few days) bought the above mentioned controller for my PS4. First time I used it, absolutely fine and this was yesterday. Today, I start my game up, everything is fine and then suddenly, the square button stops working - not responding to my pressing it at all. The M1 key works in place of it, so I figured I'd just remap everything and it would work again but nope, square button refuses to acknowledge being pressed. I have sent a support ticket, but figured I'd asked here and see if anyone has any ideas what's happened to make it stop working? Many thanks!