Minecraft 18w50a, Minecraft 19w04b, Minecraft 19w05a, Minecraft 19w06a
There exist 2 absolutely identical desert shepherd's houses. This makes the shepherd's house twice as common which prevents variety in villages.
Either load two structures listed in chat in the screenshot below:
Or open the 18w50a.jar file in the version folder in the .minecraft depository and see the following:
Delete the desert_sheperd_house_1.nbt file from the 18w50a.jar file.