Atmosphere height resets to default after changing it by modifying the atmosphere end value

I opened Droo, then decreased the atmosphere end value. the atmosphere height value in the same menu slightly above changed with it, as it should. I saved the planet. I pressed the load planet button. I selected that saved version of Droo with a smaller atmosphere end value and loaded it. went to the atmosphere tab, instead of the height being increased like it was when I saved it, it was back to the default of around 58km. I set the camera to a high altitude above Droo and playtested it from within planet studio. the atmosphere only slowed the craft down once it got to below 60km, no effect above that altitude, which, in combination with the atmosphere height value returning to default makes me think the height wasn't actually increased.