In my Custom Dimension,in negative's there is iron etc.But I just want my custom ores to spawn.

The Title explains it :
In my Custom Dimension,in negative's there is iron,stone etc.But there is only caves enabled in biomes.I just want my custom ores to spawn.Not the vanilla ones.And i dont know why this happens too.And i need help about it.

Is it always like that or am i doing something wrong?

Update : I closed ALL features but it still happens