[Karellen]

Move all my artworks from the extrafanart folder to the moviefolder. So that the extrafanart sits in the same folder as the movie and the rest of the artwork.

This is the only method that will work for you.

I find it strange that TMM is still supporting the extrafanart folder as I remember having this conversation with the developers who stated they will drop support for it. You should raise it in their forum.

Also, this might come in handy for your testing... https://kodi.wiki/view/Movie_set_information_folder