Problem: The client was unable to save the language switcher settings in the Groovy Menu on their Bellevue theme website. Despite enabling the 'Show WPML language switcher' option and deactivating all other plugins, the settings would not persist, and the language switcher did not appear in the menu. Solution: We recommended the client to ensure that the menu was translated by following the steps in our guide: Translating Menus. After confirming the issue persisted, we requested access to a staging site to conduct tests without affecting the live site. Upon investigation, we updated the outdated theme and plugins, flushed the cache, deactivated and then reactivated the WPML plugins, and finally added the language switcher in WPML -> Languages. This resolved the issue, and the language switcher remained in the menu.
If this solution does not apply to your case, or if it seems outdated, we highly recommend checking the related known issues, verifying the version of the permanent fix, and confirming that you have installed the latest versions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 open a new support ticket.