Custom post type archives returning 404 when WooCommerce Multilingual is on

Overview of the issue

This is a situation that occurs with some custom post types like it is the case of ‘Portfolio’ in the theme Trego.
– Set up a site with the Trego theme.
– Create a Portfolio post
– Load it on the front end

Expected result: the post content will be displayed
Actual result: 404

Workaround

Using WooCommerce Multilingual 3.4.4-beta2 from wpml.org/account/downloads