I have noticed that with AI factions they offer you a peace treaty but I cannot find were to accept it . This is not the regular peace treaties with normal AI player but seems to be factions that have only occupied one planet. Anyone know anything about this ?
No offense, but you do know how to accept treaties/pacts, right? Betting you do, but want to ask just in case. The rest of the reply goes under the assumption you answered yes. If it's a no, let me know, and I can help.
I'm just guessing here, but check to see if the faction has been defeated next time you see it? It would just have the crushed in picture, like broken glass. I wonder if there's not some weird fluke with defeated AIs still attempting diplomatic actions, but the player can't accept since, well, they're defeated. After reading about that bug with the occupation victory, this seems plausible, at least.
If it's not that... dunno. Do you have a save file of it happening, by chance? I'm curious.