I opened a ticket and spoke to a GM.
As far as they can tell, it’s a bug and so they asked me to post in the Bug Report forum, and to urge others to report in reply to my post. Leogrim has already linked this thread over in mine in Bug Reports, that should point the Devs to the cases reported here.
For everyone’s information and convenience, here’s the link over there: Shem of Technology not unlocking