Terrain on mobile takes up more memory than on PC?

I was doing terrain on my game and during testing, I found out that terrain on mobile takes up more memory than on PC. It was over 500 MB more. Is this a bug, because the terrain on mobile looks a lot worse than on PC yet takes up more memory?

Join this test place on both PC & mobile, and load in the exact same zones and you should see the memory differences: DMO TEST - Roblox