Multiply your paralax by 4 and they should fit?
Scale by 3 is 480x4=1920
Scale by 3 is 270x4=1080
It's so weird, all the positions got screwed up as well, so I've had to manually move all of the parallax objects in the layers as well, and put them a lot lower down that they were, and they don't line up anywhere near when I've got "parallax in editor" on. It's a huge trial and error bodge, not really sure if there's a way of getting the positions the same any other way?