Look for the "Moto" app and open it. Go to the "Moto Actions" menu and see if you enabled "One Button Nav", which allows swiping the fingerprint sensor to replace those 3 buttons. If not, enable and then disable that feature and see if the buttons return.
Have you ruled out a configuration issue with default paper thickness? I'm grasping at straws here, since I'm an hp user, but I have an hp laserjet which has jam issues if I set the default paper to "thick" when using card stock. Perhaps the epson adjusts its rollers when it thinks it needs to load thicker paper and somehow the default paper type was accidentally set to a thick paper.?.?.? Another idea is that it is an mechanical issue. Any idea if the rollers use a spring tensioner? Again, grasping at straws, but those are the first ideas to come to mind.