Thank you for the updates! I will work my way down through them now. I will also explore alternative options for the Jet Product Grid widget if it is proving problematic. Could I please also draw your attention to the single product page where there are multiple sections/ fields not showing from an ACF perspective.
In this ticket, we will handle the ACF issue on your site.
First, I must mention that I could not thoroughly check everything because, as far as I can tell, my user is blocked from editing ACF field groups. I don't see the ACF menu item in the backend.
I've made a slight change to the original product and updated its hidden link">translation with the Advanced Translation Editor. Then I could see that on the translated product, things have changed, and some of the fields do show. Please see the attached screenshot product-after-update.jpg.
If the problem is only with this specific product, you might consider editing the French version in the WordPress editor and inserting the French values for the fields. Please see the attached screenshot manualy-insert-fields.jpg.
Please let me know if this information helps you solve this problem.
Please note that my weekends are Friday to Saturday. If you need further assistance, I'll be available to continue checking this issue and helping you next week.