This thread is resolved. Here is a description of the problem and solution.
Problem: I am unable to sync menu items to secondary languages.
Solution: The items in your menu must be translated in order to be able to sync them to a translated menu. So, if the page has not been translated, it cannot be added to the menu. Once you translate your posts/pages, you will be able to sync the menus.
This is the technical support forum for WPML - the multilingual WordPress plugin.
Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.