Admin language switch on new post removes subsite from url

Hi,

I am using Polylang in a network of sites. The subsites are located in subdirectories which creates urls like this.

site.example.com/ => main site => splash page
site.example.com/be => Belgium site => polylang languages = nl fr en
site.example.com/nl => Netherlands site => polylang languages = nl
…

Now when creating a new post for example the language is set to fr by default. If I select nl in the drop down list it will redirect me. But it redirect me to site.example.com/wp-admin/post.php?post=85218&action=edit instead of site.example.com/be/wp-admin/post.php?post=85218&action=edit

So the subsite is removed from the url which results in the following error:
You attempted to edit an item that doesn’t exist. Perhaps it was deleted?

Joren