game not very responsive to inputs

This is not new as of the most recent update.  It's a problem that has persisted since the previous version.  The game is not very responsive to inputs.  Sometimes I have to click on things several times to get them to select (I can hear from the game's sound effect that I am, in fact clicking).  Double clicking to select groups of things does not always work.  The game will sometimes randomly deselect things I have selected, even if I'm not touching the keyboard or mouse.  Sometimes if I have a group of things selected and I try to shift+click/drag to add more of the same type of thing to the group, it will instead unselect the whole group.

The game seems to run fine otherwise.  There's not much lag or any indication that it's a performance issue.  It doesn't seem to presage crashes or anything like that.  It just... doesn't respond as it should.