'Cannot deserialize a 'List<String>' from BsonType 'String'

Hi all
can someone explains the next issue

I try to get data and have the error 'Cannot deserialize a ‘List’ from BsonType ‘String’
My data model has
public List<string>? Genres { get; set; }
Mongo shows data as an array

when I take data as BsonDocument I show an array

but when I try to use poco-class I have the error 'Cannot deserialize a ‘List’ from BsonType ‘String’

it is my query (but doesn’t work totally when I use poco class)

         var distinctItems = movieCollection
                        .Distinct(x => x.Title.Genres, filter)

I have tried to add [BsonRepresentation(BsonType.Array)] but I have the same error

Please help to fix that. Thanks

I have added the next GroupBy query works correctly without error

  var dataCount = movieCollection
                               x => x.Title.Genres.Select(g => g),
                               x => new
                                   Genre = x.Key,
                                   Count = x.LongCount()