Witch Huts may be interfered with by nearby biomes.

Myself and at least one other player have encountered interference with Witch Huts operating correctly (we have found a couple of Witch Huts that clearly do not have this problem). If the Witch Hut is too close to another biome (at least partially on the same chunk) the other biome may cause hostile mobs other than Witches to spawn in them. This may completely override the Witches ability to spawn in them properly.