Problem: You are developing a multilingual site using WPML and are facing an issue where content from one language and page overwrites content on another language and page. Solution: We recommend updating your WPML plugins to the latest version to resolve this issue. This problem has been addressed in our latest release, version 4.7.6. You can find more details on this fix in our errata: Editing Translated Posts Directly Can Result in Lost Content.
If this solution does not apply to your case, or if it seems outdated, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have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. If issues persist, please do not hesitate to open a new support ticket at WPML support forum for further assistance.