New Twist on Emergent Behavior quest bug? Need help

This is my 5th FO4 PT, and I've never had a problem like this before. I'm trying to progress Emergent Behavior. Yes, I completed Dangerous Minds first, quite some time ago. I left Curie with Amari, waiting for the caretaker. I get the message update to return. The caretaker for me in Glory, because I've already joined the Railroad. Glory is present, but no synth body is in the lounger. If I try to go ahead with the download, old Curie robot dies, but no synth Curie appears. I've tried waiting for scripts to catch up, I've tried leaving and returning, all to no avail. Sometimes the quest marker for "Talk to Curie" is in Sanctuary, but when I go there, the marker is hovering over empty air. Sometimes the marker is in Amari's basement, but again hovering over empty air.

Going back to just before entering the Memory Den does nothing. Using console commands to advance the quest does nothing.

If I use console commands to spawn in Curie in synth form, the quest marker stays hovering over space, like the spawned in Curie is a non-companion duplicate. None of the usual console commands work to make her act as a companion. She's just a nonverbal npc.

I'm mostly doing this PT for the Sims Settlement 2 Gunners War questline, so I'm nearly 100 hours into the PT and can't go back to redo Vault 81 and everything after. I've never had anything like this occur in 5 previous PTs. Can anybody help?