Hello, Ziga32,
It seems, there is a misunderstanding, “all pages” – means 1 condition for the custom header. Please reply back in your topic and provide temporary wp-admin access via the Private Content area – https://www.8theme.com/topic/header-not-translating-some-strings-with-wpml/#post-344145 , so we can create an example for you.
Best Regards, 8Theme’s Team
