Error 404 on Spanish site

Hello,

I’m using WPML to translate our site (original site in Catalan). The homepage of the site shows a 404 error when I click on Spanich on the language switcher. Also when I click on the company logo (which should also take me to the homepage).

Nevertheless, when I’m on the Spanish site and I click on the Home tab on the main menu it displays the homepage correctly.

There is a difference in the URL though, being cuinestramuntana.com/?lang=es when I click on the language switcher or the logo and cuinestramuntana.com/homepage/?lang=es when I click on the home tab from the menu.

Could you please have a look and tell me how I can solve this problem.

Thank you
Tomeu