I think it has something to do with JavaScript creating dynamic pages. Getting the same effects on NextDoor as I scroll down. Since all the page doesn't load at once, we are stuck with how the JS code handles the page, especially since FB and ND are ...
Nope. After I close "Inspect access..." and keep scrolling down, it starts to happen again. Has to be something in the javascript, since FB can't load a page via HTML. Someone needs to run a diagnostic trace on the script.