My friend and I have been having this problem for some time now, we found an old savefile which wasn't corrupted after the problem occured, but now, in this save file, if you walk into fort joy it will trigger what we suspect is the cause of the bug. In order to recreate it, either walk down the ladder down to fort joy, and walk towards griff, or waypoint to "Fort Joy - Square". This for us at least, when the host performs the task, makes the game freeze for about 10 seconds or so.
