Multiple Languages, Multiple Files

[FilmForge3d]

I have the same movie in two different languages as two different files. Based on the documentation I named the files Movie (2013).en.mp4 and  Movie (2013).de.mp4, both placed in the folder  Movie (2013) [imbdid-tt000000].
Is far as I understand they should now show up as a single movie with the option to select the language as it is possible with two audio files baked in, but they don't. Instead I have two separate movies next to one another.
Is there a way to merge them without reencoding the files?

[theguymadmax]

You did not name your files as the documentation states for multiple versions. 

The part before any suffixes MUST be exactly the same, including any years and/or metadata provider IDs. 

Movie (2021) [imdbid-tt12801262]
├── Movie (2021) [imdbid-tt12801262] - 2160p.mp4
├── Movie (2021) [imdbid-tt12801262] - 1080p.mp4
└── Movie (2021) [imdbid-tt12801262] - Directors Cut.mp4

[FilmForge3d]

I just checkt my library and they are in fact exactly the same before .de.mp4 or .en.mp4
Turns out the movie in question didn't need the imdbid, but I will keep this in mind when I have different versions again.