I don't know about this not working against other players in the area, but I do remember during my daily runs, there was 2 missions where I couldn't force push npc's off the cliff face, one of the missions was the one where you had to deactivate the shield generators in the landing zone, and the other one was where you're going around trying to reactivate the drills on the mesa that is crawling with mini-isotope 5 droids.
Again, not sure if this is related too much with pvp or if it even affects other pc's, but needless to say I wasn't too happy with this "force field" blocking my attempts to force push npcs off the cliff. Even with a force choke assist.