AI leaders of infantry squads sometimes lead their squad back and forth, repeatedly in circles, instead of toward their next waypoint. This can happen even if they are miles away from nearest enemies. They will continue doing this seemingly forever, I've seen them do it for more than 45 minutes.
I've only ever seen special forces and sniper AI leaders do this. Which leads me to believe it is a problem caused by high skill level. (General or Command skills, I presume).
If a player moves near the group, sometimes it will cause them to start moving toward their waypoint.