Waiting for author
Overview of the issue
Premmerce Permalink Manager allows you to set a non-standard product permalinks.
- Normal WooCommerce permalinks look like: /product/sample-product/
- The ones that Premmerce Permalink Manager set allow you to remove the product base: /sample-product/
However, this causes issues in the secondary language as WPML Multilingual & Multicurrency for WooCommerce still uses either a translated product base or original product base in the URL.
Workaround
Go to WooCommerce → WooCommerce Multilingual → Store URLs. Change product base translation to / and save.
Next steps to resolve this issue
Unfortunately we’re unable to provide a permanent fix on our end as this will require some changes from the author. We’ve already reached out to them to explain the required fix, but it can only help move things along if you let them know this fix is important to you on their support forum.