Overview of the Issue
The product variations don’t sync correctly when the term used for generating the variations is in the situation that the term_id value in the database is different than the value of term_taxonomy_id.
Workaround
This issue is fixed in WooCommerce Multilingual 3.6.5. Updating solves it on your site, so you only need this workaround if you can’t update yet.
1. Download WooCommerce Multilingual 3.6.5-beta1 from the WPML.org downloads page.
2. Run the variations synchronization again or update the original product.
