There is a simple explanation for this. Not all the movies are recorded in native 4K, many of them are in fact simply reworked in post production from a Full HD resolution to a UHD (4K) resolution, which therefore cannot guarantee maximum quality. With Real or Fake 4K you can immediately search for your favorite movies and see in which native resolution they were produced. Moreover you can simply browse the library composed of more than 550 movies all in 4K (native and not) to choose which movie to watch in the evening. In fact, in addition to the resolution, each film has a lot of other useful information like plot, director, YouTube trailer, release date, HDR etc ...
If you dont know which movie to watch in the evening, use the "discover" feature to let you find new movies to watch, based on the movies you saved in your favorites.
If you are browsing through the catalog and find one of your favorite movies, save it in your favorites to make the "discover" feature more accurate.
Furthermore, if a particular 4K movie is not present in the catalog, it is possible to request its insertion through the appropriate "+" button, located at the bottom right and always visible. The submitted film will be added within 3-5 working days.
In addition, maybe when youre in a store, with the "Scan a movie" function, you can scan the barcode on the back of the 4K DVD / Blu-Ray box set, to find out more quickly in which resolution that particular movie was recorded.
If you are browsing the catalog and you find some movies that you might be interested in, save them in your watchlist so you dont lose sight of them.