Good afternoon Merijn and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
Would you mind providing with a specific example URL where this is the case ?
Based on your description this is very similar to the “All posts (display translation if it exists or posts in default language otherwise).” setting.
The other things worth trying out are:
- Temporarily deactivating and clearing WP super cache
- Re-saving your permalinks
- Clearing WPML’s cache: head over to WPML > Support > Troubleshooting page. Once you are there, you should see several cleanup buttons. I would recommend: clearing WPML cache and using the button that forces language assignment to items (which is what is creating the issue). This can also be accomplished by deactivating and reactivating WPML.
- Adjusting translate link targets using the button found at the bottom of the WPML > Translation Management > Multilingual content setup tab
Hang in there!
Geoff B.