I have managed to make the Intenationalisation module work to translate resource labels to Arabic, by adding translations in the Translate tab.
The same does not work with Navigation labels - adding translations has no effect. I have also tried to add the the translations to ar.po/ar.mo in application/language folder but this does not do the trick either.
I understand the navigation rendering is handled in /vendor/laminas/laminas-view/src/Helper/Navigation/menu.php, and I wonder if anything else should be done to get the navigation labels translated when the site language is Arabic.
Thanks!