Fix media detection for single video files with subfolders (#14140)

Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs

@@ -456,8 +456,9 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
             {
                 var videoPath = result.Items[0].Path;
                 var hasPhotos = photos.Any(i => !PhotoResolver.IsOwnedByResolvedMedia(videoPath, i.Name));
+                var hasOtherSubfolders = multiDiscFolders.Count > 0;
 
-                if (!hasPhotos)
+                if (!hasPhotos && !hasOtherSubfolders)
                 {
                     var movie = (T)result.Items[0];
                     movie.IsInMixedFolder = false;