Problem: The client reported that translations originally created with the Classic Translation Editor (CTE) were unexpectedly opening in the Advanced Translation Editor (ATE), despite the setting to use ATE for older translations being disabled. Solution: We investigated and found that the posts in question had been previously edited using ATE, which caused them to continue opening in ATE. We manually switched the editor for the specific post back to CTE. To prevent this issue, ensure the option 'Use also for old translations created with the Classic Translation Editor' remains unchecked in WPML → Settings. If you encounter similar issues or prefer to use CTE for other posts, please inform us, and we can apply the same adjustment.
Please note that this solution might not apply to your case if it's outdated or not relevant. 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 the issue persists, please open a new support ticket at WPML support forum.