Yeah CoM is not working right for me either, and they're one of my favorite civs to play simply for the new UNE origin rival mechanic. I think they do spawn, but not as an empire. In my last game I started as CoM, I found Sol with the UNE as a primitive empire. Also, when playing as UNE, CoM will spawn as a legitimate empire, but their homeworld, Unity, will have variable climates. I tested it out in about 5 quick observe games and saw Unity as Savanna, Ocean, and the proper Continental. Seems to spawn Unity's climate at random.
Another thing that STILL hasn't been fixed is the fasces flag under human flags. I was making a custom SPQR Rome civ and figured SURELY this must've been fixed by now, considering I reported it in the bug section like a year ago. But no, it's still not working right. Such a minor thing, too.
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