Realm Of Light I - The Worm Holes Starter Glitch

Hi there, I'm having a problem with starting the Realm of Light I quest.
On our way to a part of An Iron Heart II, my partner (Xee_) and I triggered the start of the realm of light quest - the part where all the miners fall into the pit. However, we then left to finish an Iron Heart. We've now come back to properly start the quest, and the NPC Malo has disappeared. We've tried logging in and out, but it just won't let us start the quest. Any clue how to fix this?

 

Unload and reload the chunks, that usually restarted the cutscene for me.