Delete watched status of videos not been scanned into library

Hi, I would like to delete the watched status of videos that have not been scanned into the library. Sometimes I save videos in the download folder and name them for example “1.mkv”. After watching, I delete the file. If I now save a new video “1.mkv”, kodi remembers that “1.mkv” was watched, although it is a new video. How can I delete this or where does kodi store this information? Thank you very much.