Quickly referencing the Rules suggests to me that this might be your problem:
"There must be at least one Worker NPC in the facility/station managed by the production faction managing the facility/station."
If you hired them, I'm going to guess you didn't assign the faction as Manager on them, yet.
In future, for problems specific to your role in a faction, asking your superiors in your faction is probably the best place to start. You're more likely to find they have experience in your specific issue than those of us who happen by this forum.
"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."