That happened to me too but Alexa and Dr.F were outside the lab door and they were merged
together, Alexa kept saying she was going to the mission control so i tried going to a
different island and coming back and saving the game but i had to delete what was under
them and they walked out. I'm not too sure what you could do though.Maybe you could just
wire up the computers and do everything that you would need to do up to the video where
she at mission control (what i had to do before in Cowboy Junction)