[تم الحل] Translate labels ACF checkbox

Background of the issue:
I use the Advanced Custom Fields Multilingual plugin. Within an ACF field group, I added a checkbox with the following values: nl : Dutch, en : English. I am following the documentation at https://wpml.org/documentation/related-projects/translate-sites-built-with-acf/.

Symptoms:
When I go to 'String translation' all the ACF labels and options are translated. Unfortunately, when I go to the Dutch frontend, I still see the English values.

Questions:
Any idea where this goes wrong?