I am playing as Rome and found Brazil. Traded a few items, he seemed to like me. The slider was very positive and the current standings were +5, +2, +2 and -2. Then Brazil and myself declared war on me.
So I have a clone. I knew about that bug, still weird. But this clone did not met me before. Nevertheless he declares war on me. And of course both AIs did not want this war, so they did not send a single unit. A few rounds later Brazil made peace and gave me some gold. And that's when I noticed that this bug is a huge problem. I could not make peace with Alternative Rome! I had a very long war in my game before and it really hurts, most of my cities went crazy and started to spawn Barbarians. I don't want to repeat that, so my only priority now is to build some ships, sail across the Ocean and find myself to make peace - and get some gold, as always
In less than a week I have found so many bugs, it's absolutely terrifying. I cannot name a single feature that does not have multiple major bugs (and by "feature" I mean something bigger than just "Fortify"). Especially trading is so broken that I don't know how to write down every bug I found so far. The whole system is not working as intended.
Don't get me wrong, I like Civ 6 and I hope that those bugs get fixed soon. However the current state of the game is everything else but stable. To me this is not a release version, this is early beta. The game feels and looks unfinished and rushed.
TL;DR
1. There can be a "clone" of the player.
2. The AI can be part of a joined war against somebody they did not met before which is a huge problem.
3. The AI declares war for no reason, does nothing and than makes peace for some gold.
4. Trading needs to be looked at, so broken...