This problem is currently happening with the game Wolfenstein II: The New Colossus. Sometimes it shows up as "Unknown game" and other times I have multiple entries for International version, German version and each DLC listed.

Yesssss! That's it! It's Wolfwenstein The New Colossus all right! Thank you! Not only I was getting mad to understand what this Unknown Title could ever be, but also I did not notice any title not listing; not that I had that many, right, but still...
After your answer, I could in fact determine that it was it!!
Thank you again!!!