I've been using this code to create a world weekly for a few years. I started having this problem after the update to 1.19.3.

My code:

WorldCreator creator = new WorldCreator("sampleWorld").type(WorldType.NORMAL).environment(Environment.NORMAL).generateStructures(true);this.plugin.sampleWorld = this.plugin.getServer().createWorld(creator);

I fully deleted my world and re-created it this this, but it's super flat mode instead of normal. My only WILD GUESS is that it might be related to my default world's mode, which is super flat.

It should be unrelated, but I have specified minecraft:normal in server.properties.

I'm stuck in a big way because my players need this additional world for resources.