iPhone X keyboard adds extra letters

I have an iPhone X that has never been dropped, come into contact with moisture, or any other form of shock or abuse. For the last several months, my keyboard has started to go haywire, adding extra letters, typing when I'm not touching the screen, closing apps, shifting through my apps, reopening the app it just closed, typing more letters, etc. in an endless cycle of not being able to use the $1200 investment in my hand. I restart the phone and sometimes it fixes it for a few days, and sometimes just a few minutes. A hard reset had it malfunctioning at the password screen before even opening for the first time. I've disabled predictive text, auto correct, auto capitalization, etc to no avail. Why is this happening?