Export panel bunches itself in top-left corner

Occasionally when trying to export, the new export tab/panel/page won't fill the full window, but will instead bunch itself into the top left corner (in the space the source monitor is in my workspace). 

Setting aside how this seems to indicate that the new page is in fact an ordinary panel, and how easy it would be for Adobe to just make it a window again, this does make it somewhat annoying to actually export.

This mostly seems to happen when using the Ctrl+M shortcut, rather than when clicking the "export" tab on the annoying, space-wasting, unclosable toolbar.