So I have two rabbits who have been bonded for almost a year now. They’re both fixed. Their initial bond was super easy. One bathtub session, no fighting, and they were in the same cage that night. Everything was fine until about six months later. They had a huge fight; there was fur everywhere and they each had a few minor scratches. It took me a month to rebond them that time. Since then every few months they have a fight. I have no idea what triggers these fights. To rebond I put them in a laundry basket for awhile, then downsize their cage for a few days and that usually works. Now it takes me anywhere from a few minutes to a few days tops to rebond. 

Does anyone else have this issue? Is there anything I can do to try to prevent these fights? Would getting a third rabbit maybe help the dynamic?