I’ve noticed that some systems show up in the Clever/Creative/Challenging rankings without being available in the regular system list. There are 38 systems listed in “Others’ systems” and I have 9 public systems, but there are 77 systems in the rankings list. One thing the extra systems have in common is that they are all in clusters, but some of those clusters aren’t public.
This does not happen in the clusters lists.
Some examples of the “extra” systems:
https://exploitzeroday.com/system/Ak56mg/
https://exploitzeroday.com/system/Arq4qd/
https://exploitzeroday.com/system/GkM73d/