I went to your live site and checked the product listing on the Dutch page and saw that some products are now showing, presumably ones you have saved.
I re-saved all of the product posts (the originals) using the WordPress bulk edit option, but without making any changes, which is enough for the custom field value to be copied over to the translation.
Now when I visit the product listing page in Dutch it shows all of the products as far as I can tell.
I think that if i go the dutch product pages i get scared away by a message that all is created in the primary engels language.
How did you do the bulk editing to resolve my issue (maybe a few screenshots pls still confused what i did wrong)
Oh, and if I want to continue and add more product images (gallery) in the products that still need them (change the product posts) that the view gets broken again (as you said before i believe?) ??
The English language versions of the products are the default language posts, yes? And the Dutch products are translations?
The English product posts had the custom field value which needed to be copied to the Dutch versions of the posts (after changing the WPML setting for the custom field from Do not translate to Copy).
So to trigger copying the custom field value (which is handled by WPML), you need to save the English language versions of the posts.
So I bulk edited the English versions (from the product list in the backend select all the posts, then from the bulk action menu choose edit, then update without making any changes. You have to do that on each 'page' of products, of which there are fortunately only two.)
The original problem with the gallery was when you were translating the template with the gallery (which will be fixed in the next version, a beta of which is currently available).
You should be able to add new posts (in English) and translate them to Dutch without having to do anything special.
"The original problem with the gallery was when you were translating the template with the gallery (which will be fixed in the next version, a beta of which is currently available)".
So better to wait with adding more gallery pictures to products (who have none yet) in the individual product posts till the WPML update is out of beta?