Unable to change the language switch link text to iso code

I have three languages and a primary set-up. For one language, the link text in the switcher is set to name whereas the others are set to iso code. The latest language I have just added defaulted to iso code. If I navigate to the text in the designer the option to change the value from ‘name’ to ‘iso code’ is inactive and I can’t figure out what needs to happen to unlock it. Any help to show me the obvious answer is most welcome!

https://preview.webflow.com/preview/barcelona-attractions?utm_medium=preview_link&utm_source=designer&utm_content=barcelona-attractions&preview=a834bdd8f18d91ff5ec13bc741325a1f&locale=es&workflow=preview