That quest didn't give a title. It gave nothing except an achievement.
You receive your Zeta and the "Z" title together. THEN he has a red locked quest... which was very easy to overlook since for many people he ALWAYS had a red locked quest.
But yes, let's blame players for SE's bizarre coding decisions and poor patch notes. "If you possess a zeta you'll be able to buy a replica!" (false). If you completed an arbitrary quest which was in no way necessary to get your zeta, you can buy a replica.
Anyway, at least they're fixing it.