Not sure what could be causing that. Best thing I can tell you to do is to delete all the files associated with the game, re-download them and try it again. Maybe its some kind of glitch with MV3D? I can't replicate it, and unless more people start experiencing the same issue there's not much I can do about it right now :(
Viewing post in Scarlett Rose in the Wide, Wild Wastelands comments
The disk space returned back after a couple of days, I personally did NOTHING to return them, it did it itself... It's strange, I'm not a programmer at all and am far from this, but it feels like the game after it uses the disk space during the game, it takes it but doesn't know how to give up free space after using it, and gives it up after a long period of time. But that's just my thoughts out loud.