Background of the issue:
I'm trying to import or update translations for products in a secondary language using WP All Import. I have configured it to find products by a custom field '_sku' and mapped the SKU field. However, WP All Import is using a unique ID, which is only set when importing new products.
Symptoms:
The import process skips all products because it incorrectly tries to find them by unique ID instead of SKU.
Questions:
Why is WP All Import using a unique ID instead of the custom field '_sku'?
How can I ensure that products are found and updated by SKU during import?