It's not a bug in the common sense, but for me nevertheless a bug.
I'm playing a game at Painful level, medium map, 6 opponents.
Atm I'm at war with the Iconian Refugee and while I have seen already some things from the AIs that make me go "umm", that was really the most extreme I had seen so far and only makes me shake my head:
So the Iconians had discovered one absolute dreamplanet: with a 700% manu bonus tile AND a 300% manu bonus tile.
Holy sh** thats quite some production power there. Right? no...The AI actually did build an Extreme stadium and a Banking center there. sure.....
That it built an Anti-Matter Powerplant on this planet without a single Factory on the planet is already harmless compared to that...

And another one, not fully in the same league as the above but still stupid nevertheless:
Their homeplanet. They build the Economic Capital AND the Tech Capital AND the Manu Capital there. I wouldn't do that, but ok. But they dont have a single other econ building there and just a single factory which truly wastes the Manu capital.

All in all this is as poor as it gets. Not sure if the AI acts also the same way at the higher levels, but imo at Painful it has all abilities available and truly shoudln't act like that.
I mean com'on....700%-manu-bonus-tile = a factory tile. The AI shouldn't even have to think about that and in all honesty I cannot imagine that this could be in any way hard to code.