I read on Zam that after u hit 38 u have to wait till next leve reset & then when u next visit an Aetheryte the npc linkshell will glow.
After the following leve reset i clicked on nearest Aetheryte and nothing, the npc linkshell didnt glow untill i was at Camp Black Brush, i had been to about 3 or 4 camps before it triggered