We just upgraded from 4.3.1 to 5.6.3. Unfortunately the now-rounded Search bar does a full site search. We use the Documentation theme, and the "Limit search results to the current space" check box is selected. Curiously, a Search box appears in the left pane above the page tree only when this check box is not selected, the opposite of what I would expect. At least this left-panel search box is space restricted, but it would be nice to be able to get the space restriction applied to the Search box at the top right of the page instead. How do I do this?