Realm member lists are not pulled with case sensitivity.
Example
I had my realms named EPIC for a while. Then one day my realm members went way up on rankings for no reason. The number of realms was the same and I only give access to 1 other person on ALL realms.
I just figured out today that his realms were named epic. The plot counts were querying correctly but the when the members list populates, it is not maintaining case sensitivity on the realm name.
I hope that was clear enough
Editing to confirm that after changing my last realm to the new name (thanks /realm list command ), Mike_kun was no longer randomly showing up as a member on my rankings.