I think this is the one causing the desert to be generated :P

It also has desert as base... when i turned it off it became a the exact same land as the vanilla desert

Hmm, that's odd... what's even more bizarre is that the new Desert generates perfectly in a single-biome world. Maybe the two are bleeding into each other too much during generation?

That's why I think he's the culprit

Because it's always bordering the savannaplatue