I have noticed this for several weeks.
I lead a group ride every week we have been doing the same course for the last 3 months, so I would assume that if the PR are indeed for the last 30 days then there should be atleast 6 entries in the PR listing. But it seem to only show the current week.
I don’t know if this is only a Bologna issue.
this is from the last group ride going up the KOM in Bologna.