To use 'Page Public Content Access', your use of this endpoint must be reviewed and approved by Facebook

I got Facebook app review approval

No, you didn’t ...

You filled out all the necessary info, so that you now can submit your review - that’s what those green check marks mean.

If you actually had this reviewed already, then it would show a green circle in front of the permissions, and would not show “Edit Details”.

If you are stuck in an infinite loop of app approval (Facebook doesn't want to approve your app because "use case data is not visible") I think that the only solution is to temporary create your own page (or use some of your existing pages) and then crawl that page's content.

Here's what the Facebook say about "Page public content access":

"While you are testing your app and before you submit it for review, your app can only access content on a Page for which the following is true: The person who holds the admin role for the Page also holds an admin, developer, or tester role on the app. If you want the app to be able to access public content on other Pages, you must submit this feature for review. Once you set your app to live mode, it will not be able to see any Page public content without this feature."