For posterity, and anyone else that had this issue - the achievement appeared when I:

• 1. Saved and closed the game

• 2. Opened it again later

Mystery solved, although that seems like a bug.

Hey All,
Playing Factorio through Steam (0.16.x pre-release) and made a solid attempt to get the Tech Maniac achievement (research all technologies). I had previously tried on 0.15.x, but realized that simply researching one instance of each tech was insufficient - you have to get Space Science ...