Unless I am missing something, it seems like this is a pretty major bug, preventing normal play.

If I double click a planet with a construction yard, then right click on the construction yard, and select build, I am brought to the "Build Selection" window as expected. However, clicking on the downward pointing arrow which should allow you to select a different item to construct (for example, shipyard or training facility) does not seem to work. The button animates the click, but no additional popup or window appears. This seems to make it impossible to build anything other than more construction yards, the default.

Similarly, if I try to send someone on a mission, I cannot select a new mission. The "Create Mission" window has the same problem where pushing the downward pointing arrow does not allow a new selection. For example, with "Veers" selected I should be able to choose a training mission, but I cannot, I am stuck on diplomacy.

EDIT: OK, so this appears to be a problem with windowed mode. When I click the downward arrow button, it looks like it causes the window to lose mouse focus for some reason. Things work as expected in fullscreen mode.

Unfortunately, on my machine fullscreen mode seems to have about a 50% chance of locking me up with a black screen.

I tried it in window mode. It works for me with the construction.

EDIT:
Ok it doesn't work every time. Sometimes it works, sometimes not.

OK I think I figured it out. In windowed mode, the construction popup is shifted based on the coordinates of the game window. So, if your game window is in the upper left corner of the screen, then the popup appears. If your window is too far down or right, the popup appears outside of the window bounds and you can't see it.

Lol.Very annoying.,

This is the correct answer