The layer in level 2 has 0 parallax. That's not default, so you would have had to go out of your way to set it. I mean there's only one layer anyway so why fiddle with it?
You have scroll to enabled on two objects, playerbox and astronaut. They also both have 8direction on, so there's not really any point to having two objects the way it's set up right now.
Not really my place to say this but this project has way too much going on for what it is trying to do. If you're guiding students I'd recommend focusing them on doing the minimum of only what is necessary to reach the desired result, for their own future sanity and yours as well.