Resolved

Reported for: WooCommerce Multilingual 3.7.12

Symptoms

The path of a downloadable product is always synchronized between original and translation.

Workaround

In wp-content/plugins/woocommerce-multilingual/inc/products.class.php
On line 906, you need to change:

if( in_array( $key ,array( '_file_paths', '_downloadable_files' )) || ( isset($settings['translation-management']['custom_fields_translation'][$key]) && $settings['translation-management']['custom_fields_translation'][$key] == 1 ) ){

to:

if( ( $woocommerce_wpml->settings['file_path_sync']  && in_array( $key ,array( '_file_paths', '_downloadable_files' ) ) ) || ( isset($settings['translation-management']['custom_fields_translation'][$key]) && $settings['translation-management']['custom_fields_translation'][$key] == 1 ) ){

Or apply this patch on that same file mentioned above: 5cfd9c862c0da207262c5da49d6608f7ae1d25d0.patch