3D password animation issue

I am having issues creating the 3D animation for the password. I’ve deleted everything and their categories more then once trying to fix the issue and tried adjusting the parents to different settings. I cant seem to get the the boxes to move backwards on the Z-axis they just disappear. Im 9:33 seconds into the 21 day portfolio course on 3D parallax. Any help on why this isnt working right would be greatly appreciated