So my server is 6 years old. I was always updating the bukkit and now I'm running on 1.12. When I'm generating new world, it's amazing. Crazy mountains, forests etc. But my good ol' world doesn't seem to get the same treatment. Even though I'm discovering new terrain that wasn't discovered before, it's still plain old. I do get the villages, ocean temples, horses and llamas, but no fancy new biomes. Is there something I should change in server settings? Or maybe it's like a chain reaction with the old generator and I have to look further? Any advice will be appreciated.