I’ve tried this twice now and had a different problem each time.
The first time I cleared the room with the first orb in but when I tried to push the switch to get the fight scene it wouldn’t let me, and i couldn’t talk to the npc either.
The second time I went through that bit fine, collected the 2nd orb but had to fight before putting it on its pedestal. During the fight the orb disappeared and I had noway of getting it back.
Anyone else had these problems? Not found anything about it on Google, but the amount of problems I’ve had in my storyline and needed to restart missions is ridiculous.