We ran into an issue in our game today, and I'm just wondering if anyone else has seen this or might know a solution.

One of our players is (well, was...) a ranger. Every time he would use animal companion (after level 5, this wasn't always the case), it would instantly aggro him and start a combat. No one else had him marked as an enemy, only the ranger. We once tried attacking it when we were in camp, and Astorian ran over to heal it. If no one made any moves and just ended their turn, the combat rotation just went in circles and nothing would happen. Does this sound familiar to anyone?