It has happend to me in the last 4 games. In the mid-late game the sectors stop building anything but energy stations. No mining stations, research, observation post or defensive stations are build after some hours playing the game.
What is their focus and what is their budget balance? Sectors seem to always want to generate an excess and they happily ignore anything that is not part of their focus especially if you have a lot something already. My research sectors barley give energy and minerals but a lot of points. There are also quite a few of untapped mineral depots too.It has happend to me in the last 4 games. In the mid-late game the sectors stop building anything but energy stations. No mining stations, research, observation post or defensive stations are build after some hours playing the game.
Instead, how about suggesting a 'allow orbital construction' for the sector controls. That way, you can prevent the sector from building any research/mining stations and instead do so manually.