Ps5 controller worked fine next day dosnt work fine 😔

Hi has anyone had or no why my pad went from working fine to now not when I press the x button the pad will bring up the short menu as if I pressed the PlayStation button and when I turn it off the pad keeps coming on by it’s self even with ps5 unplugged from wall any one had this problem befor and yes I fully charge the pad of the ps so it’s had full battery but still same problem any help don’t want pay 70quid for new pad like I have reset pad to and reconnected it and that didn’t help