Lt Harris' arc via Ouroboros - No Arachnos Prisoners to rescue

I'm flashbacking Lt Harris' arc via Ouroboros to get the Freedom Cracker badge. I've gotten as far as the Release the Arachnos Prisoners mission but there are no prisoners to rescue



Anyone else had this problem?


UPDATE:
I had to petition this and get a GM to complete the mission for me. The rest of the arc was completed without issue and the badge correctly awarded.