Can you provide a specific example of how the files are named and organized?
The organization should look like:
/Movies
/The Dark Knight (2008)
The Dark Knight (2008) - pt1.mp4
The Dark Knight (2008) - pt2.mp4
See Naming and Organizing Your Movie Files, specifically the Movies Split Across Multiple Files section.
As noted in the support article, multi-part movies are not supported by all clients.
You may find it easier to join the parts into one file.
See Joining Multi-Part Movies.
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