Yep, this was mentioned a couple of days ago too but got no response. The relationship value seems to fluctuate, and the AI either rejects the pact outright (which I'm okay with) or accepts it and then INSTANTLY cancels it (which seems like a bug to me).
Also, after 7hrs in one single player game I got no missions from the AI, and no offers of pacts, despite having maxed out (20, or almost) relationship with multiple AIs.
Also, the race relations modifier is positive instead of negative, so "alien" races begin liking you more than AI of the same race.
This seems like a step back from beta 2...