Why is it that "No language" can be 2 values ?

upload and don't select language = nil

change language to any language = e.g. "se"

change language back to "No language" = "xx"

This must be a bug

please fix, and convert all existing Fanart/poster to either "xx" OR nil

Value
{"backdrop"=>{"file_path"=>"/cKlMUncISEfPjG3bUL6s1CCDP80.jpg", "iso_639_1"=>"xx"}}

Original Value
{"backdrop"=>{"file_path"=>"/cKlMUncISEfPjG3bUL6s1CCDP80.jpg", "iso_639_1"=>nil}}