Further information:
It’s only showing people who are online or perhaps recently online.
Freya logged off, and has now disappeared off my most recent leaderboard even though he/she is still listed as rank 10 in the profile.
Also Boar and Livluv have just popped back up after not being anywhere in the top 100 within the span of a few minutes seems highly unlikely given typical raid duration. More likely they came back active and now show up on the leaderboard confirming the issue.