I've noticed that the (only) first tab of the page properties dialog of certain pages shows vertical and horizontal scrollbars. I've checked that in all browsers, and it's there in all of them, except Edge, MS' latest browser in Win 10.

This could be related to some height and width computation, as I see two slightly different results, depending on how you get to the tab. I would no be surprised if the problem was actually due to the checkbox at the end of the form. There's something a bit fishy about those fields, e.g. they also don't show the keyboard focus.