Xbox Elite Series 2 Controller won’t work sometimes

First the Xbox button doesn’t work and the controller won’t turn on unless it’s plugged in, but even when it is plugged in it doesn’t work but all of the other buttons work. It’s fully charged too, does anyone know how to fix that? And second thing is I will be playing a game and then all the buttons stop working except for the joysticks and only way to fix it is to spam click the profile button, anyone know how to fix these problems?

:)