None of the mentioned movies had a Dutch translation on TheMovieDB.
So next time you can do the following when you run into the same:
1] add a translation yourself and contribute to
https://www.themoviedb.orgJust create an account over there - it is pretty simple to add translations
2] or set temp the setting to English if you don't care to have English plot only.
I have just added all Dutch translations for these movies now (to show you that it will work), so you should be able to get Dutch plots when TheMovieDB has synchronised them to their api cache.
Do a rescrape tomorrow and I you sill get Dutch for those.