I conducted an activation on 26th January 2018 as AX5PAS. Although this log is showing in my own stats, I cannot see reference to this activation in the Top Operators area when I do a search for 2018 and VK.
I’ve fallen down an algorithmic rabbit hole too.
Three activations this year so far but not showing in the activators list. One as AX2IO/P (with OperatorCall as VK2IO) and the others as VK2IO/P. One had 11 QSOs and the others >= 44. One crossed a UTC day too.
So the requirement seems to be 3 references of at least 44 QSOs.
I’ll know after my next VK2IO/P activation.