I was able to replicate this behavior on a fresh installation and have already escalated it to our team for further review. I’ll update you here as soon as I receive any feedback or additional information.
I’ve received feedback from our team. As a temporary workaround, please try adding “brand” to the Product brand base in Settings → Permalinks and then save the changes (no need for further actions in WPML → String Translation as it is already translated there). This should help improve the behavior for now.
A complete fix is planned for future releases of the WooCommerce Multilingual plugin.
For now, it works. However, 'merk' remains 'merk' in all languages. For Dutch, that is no problem, but for English it should be 'brand', for German 'merke', etc. See #46.
Attachment #47 reflects the new situation under Settings -> Permalinks.
I’m glad to hear that everything is working well for you.
Regarding your other question, I recommend consulting the official WooCommerce documentation for the best guidance, as it pertains to a topic outside the scope of WPML functionality.