Hum, I just started a new game to specifically get this achievement as it is the last I need. Anyone else having this issue? I would like to know before I continue this game

Oh well, we did manage it back in previous versions, I suggest giving away even more systems! :-D
It would also seem to me, that systems that academy owns by itself do not count toward the achievment, so if you have some suspects, you might have to invade them and then give them away.... it would be the systems that do not provide tithe income.

That's not the issue—I made sure of it. I took over all the Academy systems beforehand. In that game the Academy owned only one system that I didn't give to them (the Academy system itself).