Bug in conjunction with ACF gallery field: All translated images are visible

I have an issue with the newest Polylang version (2.1.2) in conjunction with the Advanced Custom Field Plugin (5.5.10). Everything is up to date.

1) If you create a page with a custom gallery field you can attach media images to the gallery and select the language (i.e. German). That works.
2) In the next step you want to translate the page and create a new page and set the language (i.e. English).
To get the gallery field shown on the frontend, you’ll have to upload all gallery images again and set the language within the attachment settings.

The problem: On the german and english backend page all images of all translations are visible within the gallery field. In my opinion only the images with the applied page language should be visible.

Turning off the “mediafiles translation” in the Polylang settings is not an option for me, because I want to translate the default wordpress image attachment fields, like title, description etc.

Is there some kind of workaround or bug fix?