Problem: The client reported that the order of the menu items had changed unexpectedly, with the language switcher moving from the last to the second position in the menu. Additionally, the client could only select menus from the current main language, despite the display showing a menu from a previously set main language. Solution: We recommended the client to adjust the order of the languages by navigating to WPML >> Languages >> Language Switcher Options > Order of languages. This adjustment should help in setting the language switcher back to its desired position at the end of the menu. Furthermore, we suggested that the issue with the menu order might be a temporary glitch and recommended moving the navigation menu around to see if it resolves the issue.
If this solution does not apply to your case, or if it seems outdated, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. Should the problem persist, please do not hesitate to open a new support ticket with us for further assistance at WPML Support Forum.
