When I press any of the keyboard shortcuts that select an operator for building (by default the number keys + minus + equals + slash for spawner), if the build bar is currently not on the operator tab, it stays on the current tab, and the selected operator's description is not shown. This makes it hard to figure out what is actually being selected, especially for shortcuts that can cycle between several operators, since the only visible hints are the translucent operator under the mouse cursor and the shortcut list (the one that says "Left Button to place").