On my 2016, the leveling system is made by Equalizer Systems and is hydraulic. (https://eqsystems.us/product/class-c...chevy-chassis/
One slipping down seems like it could be a leak, or valve that needs to be snugged up.
Someone else may know more - but when I reached out to Equalizer for a different problem on mine, they were VERY helpful! I give their tech support five stars. We exchanged emails, pictures, video and they helped me fix my problem.
You may want to start by contacting them first