1 point
It depends on how the source categorized the information and how Microsoft classifies the Xbox One versus the Xbox One Series (whether as being two actual different consoles, or two versions of the same console.)
https://en.wikipedia.org/wiki/Category%3ASingle-platform_video_games
There is only one entry for anything related to Xbox One as far as I can see so I expect the 12 it notes are distributed across all versions of the Xbox One, or that there are 0 dedicated games for the Xbox One Series proper.