Thanks spycat. I just confirmed it is scraping as Windows as you suggested. To confirm the formatting of the title I cut and paste it into notepad and back and everything looks correct. Weirdly it has identified ACIII Remastered just fine and to test I cut and pasted just the Assassin's Creed III part from that title and still no joy,
It seems so random what it can't identity - Dead Island, Persona 5 Strikers, Meet your Maker for further examples. They do all come from Steam, could maybe this be the problem?