alien bug

[Grondavor]

I have noticed that the name of probe aliens have been randomly changing when an alien commander appears.  for instance, several times i have been at an alien terminator, and an alien commander appears.  the commander is too powerful for me to kill, so i go to a different alien.  After this alien is dead i go back to quadrant map and see for instance an alien hauler.  I go to the alien hauler only to find that is the alien commnader of the alien terminator i had gotten earlier....  I dont know why the terminater has randomly changed to a hauler, all i know is taht i have wasted 5 turns traveling to it expecting to find alien haulers...  and this has happened to me several times.  Any idea why its happening?