I have already reported the same problem via the issue tracker and got an email saying they are looking into.
In case if it helps, I did not follow the two NPC options to enter the Vox Relay and I got the same issue after hailing Inez - who surprisingly introduced herself, joined my squad and then we fought the crabs to get her the arm and completed that quest and then as soon as she got her new arm, she had the NPC dialogue box over her head which prompted me to hail her and then got the same dialogue option as the OP and then she left.
Lol, i felt what an amazingly scripted moment that she duped me into getting her arm and as soon as she did, she fled...only for me to later find that she has permanently left.
I think if this was intended and you had a myriad of different companions to go through (i.e. not just a few) this would have been a great little twist in progression but its not sadly.