there is a bug that messes up the parachute deployment altitude
how to replicate
drag two or more parachutes
activate ASL deployment to all parachutes
click on one parachute and activate part properties so you can see the bug's effect
change the environment (of the design info) to a random planet with an atmosphere
and at last click on one of the other parachutes (or the second one if you dragged only two parachutes) to realize that the altitude of deployment has indeed changed.
I believe that when you change the environment on one parachute and then you change to another parachute the game doesn't acknowledge that the parachute you clicked has ASL deployment activated and leaves the sliders as they are changing the deployment altitude instead of adjusting the sliders to the correct place to maintain the altitude that was set before.
@FlammableAndRocketThings I spent 4 months building a 6,000 part craft and nobody wants it 😢. I feel you.