I am using WPML in a 2 languages site (ES & PT-BR) developed with the Elegant themes' EXTRA. I am using Yoast SEO plugin to manage SEO matters.
In this site I put in the menu links to categories to list all posts within this category.
In Spanish (the default language) I get the proper post listing (ex: hidden link ) when going to my secondary language Portuguese, using the language switch or going directly to the URL, I get a 404 (see hidden link )
In another case, the Spanish category shows the post listing correctly ( see hidden link ) where the Portuguese goes on a post hidden link from this category.
I would expect to a post listing in hidden link instead.
I understood that the "Remove the categories prefix" option on Yoast could interfere for which I installed the "Yoast SEO Multilingual" plugin. I tried to reactivate the category prefix in Yoast which would solve the problem but I cannot leave it like that for SEO performance.
In the past, using this "Remove the categories prefix" option by putting "keep" then "remove" back and purging all caches, I could get a temporary fix to this problem. Nevertheless It would appear again on plugin updates.
Now with the last update, doing this fix is not solving the problem.
Thank you Andreas. if the WPML -> Taxonomy Translation was correct I could see the WPML -> WP Menus Sync was out of sync.
Syncing them back solved the problem hopefully for good. I'll cross finger on the next update.