In order for Polylang to be able to translate news items and tags, you'll need to enable our custom post type and taxonomy in the Polylang Settings area.
Polylang custom post types and taxonomies settings.
WPML
In WPML, make sure that set translatable Post Types Translation forMFN News Items (mfn_news) and Taxonomies Translation for News Tags (mfn-news-tag).
If you already have imported the news items, you should do 'Delete all MFN posts' from the plugin MFN Feed settings. Once done deleting - click 'Sync All' to import all press releases again followed by 'Sync Taxonomy' to make sure that the taxonomy has been updated.