All Nerians you approach, including gate sentries, will attack you
Use Illusory Arasai Effigy and equip Cultist Robes, and speak to a Nerian questioner (several wander near the gate). If the zone bugs out and you cannot approach a questioner to hail them, zone out and back in and then use the effigy immediately and they should now no longer be hostile.
Speak to a Nerian questioner
Watch a Thexian being interrogated ( 28, 1, 26 ) /waypoint 28, 1, 26 or ( 0, 0, -31 ) /waypoint 0, 0, -31 or ( -27, 1, 10 ) /waypoint -27, 1, 10
Watch another interrogation at a different location listed above