how to make certain pages protected

I have NO rules (positive or negative) set up. yet, I've got about 4 primary pages that are protected (which is good), and 2 pages which are NOT protected (1 working as it should, but 1 needing to be protected).

I can't find any difference in how the 1 improperly unprotected page is set up that would make it unprotected. And I don't see rules making other existing pages just not sure what I'm doing.