Very bizarre/Terrible World gen

Recently I've been encountering very weird world gen. This kind of generation has generated really tiny biomes specifically the Decidious, Both deserts, The Swamp, and sometimes the mosaic here are are some examples.

Tiny swamp and both deserts connected, tiny decidious.

Everything is mini-sized here.

Again, tiny biomes.

Tiny biomes.

These where all generated with a normal world size (Large) Disease to off, boons to more as well as a mod that forces the reed trap to generate.

There is no way these mods can affect world generation in this way (atleast I don't think they do?), and client-sided mods can't affect world gen either. But i'm going to generate/regenerate a few vanilla worlds anyways.

Good swamp and meh desert, terrible pig king.

Even when both deserts combined, it's small. same thing for mosaic and the other biomes.

Oasis is awful, absolutely terrible, every other biome except decidious is fine but why has the mosaic been connected to the decidious now?

If there is an explanation/fix for this terrible world gen, please tell me! Thank you!