Welcome to the forums. I'm not sure what you mean by "pinned". The navigation bar buttons are not available on the lock screen, only the unlock icon and a couple more shortcuts, like the camera. Have you tried swiping up from the padlock icon or using the fingerprint sensor?
Do you mean that the navigation buttons (back/home/recent apps overview) are not available on your home screen? If so, open the app drawer, tap the Moto app, select 'Moto Actions' and switch 'One Button Nav' off.