That isn't just pulled from the add on that is pulled from all the mythic + they scan which on some servers are all of them and even on the highest population servers a very large chunk of them.
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Bigger servers and servers more focused on mythic + runs wont have them all scanned. As soon as the cap for each ranking is hit the ones that fall short aren't tracked, the only way around that is if you have somebody in the group from a lower progressed server. You will also have groups that run the same dungeon back to back and one of those is often missed in the tracking. If you did a slow 10 or lower key for UR right now on Area 52 it wouldn't get tracked and we are just starting the week and it had a holiday in there to slow things down.