[Chiuso] Brand base (slug) does not translate well

Background of the issue:
I am trying to translate the brand slug from English to Dutch on my website. When I visit my English site on .com and navigate to a brand page (/brand/xxx), then switch to the Dutch site using the language flag, the slug remains 'brand' instead of translating to 'merk'. The brand slug is translated within WPML, so it should work. The issue can be seen here: link nascosto

Symptoms:
The slug 'brand' does not translate to 'merk' on the Dutch site, causing errors. Instead of seeing link nascosto, I get link nascosto.

Questions:
Why is the brand slug not translating from 'brand' to 'merk' on the Dutch site?
How can I fix the slug translation issue in WPML?