Problem with the volume and apps keep shutting down.

Well I don't know of any other way to explain what is happening. Here's an example if I was to push the up or down volume buttons it would come up and show it on the screen. Well that's what its been doing all by itself. When I am playing a game or using another app they sometimes just shut down it doesn't happen all the time. Also when I am on Facebook Marketplace it will glitch a bunch of times and it either freeze or restart Facebook. I have reset my tablet back to factory settings and it is still doing the same thing. And the battery doesn't seem to want to charge.