Map Controls Box 'footprint' is larger than the visible Box itself

When I mouse over over the Map Controls Box it becomes a cross shape and you can click to drag the box around.

The problem is the sensitive area extends all the way down below the actual Box, so trying to grab the screen with a left click in that area to scroll the map simply moves the Box. And I can't click anything on the map (province, unit) below the Box because the game interprets me as clicking on the Box.

It's as if the Box is made of 2 parts, the visible part at the top with the various controls, and then a transparent component many times larger, extending beneath the box. Can you remove the transparent part?