My son and have have about 50 hours in playing via LAN multiplayer. For that first 50 hours, if we wanted, we could go off on our separate ways and go to different zones without any issues.
However, now anytime one of us zones into a new area, regardless what the other is doing, they get dragged into the same zone/spot.

Is this a bug? I didn't see any group setting that would have changed this.