Make sure to turn on the camera perspective by applying the photo_mode_active transform to the camera as shown in the FAQ and How To Install. It's a 3D camera so it needs perspective to be turned on. There's a YT Shorts and the longer tutorial if you need it.
I don't have "new_bg" defined anywhere inside Photo Mode so that must be somewhere in your project.
Note that if you dont tag you backgrounds with "bg", the far transform won't be applied automatically and there will be no parallax unless you manually set the zpos yourself.