After rendezvousing with the smuggler, I paid the inflated price and took the crates towards Sayuka.
Iverra appeared, and we spoke.
On arriving at Sayuka I used the Quick Travel menu (from the map when initially docking) to go directly to the workshop.
This caused the 'go dive here for this' cutscene' to play.
Then when I left the worshop the camera panned to the Docks where Iverra played her 'Ah, Sayuka, thanks and bye' cutscene.
The journal tells me to talk to Fleet Master Okaya, but her only dialogue is the speech-bubble 'Fight or Flee as you like, just stay out of my way."
As a result I don't actually have the next quest, and progress with a major faction appears to be completely blocked.
I can't post the savefile since it's enormously larger than the file size limit. If you have a preferred rehosting site do please let me know.