I got the message: "There is a problem with the String Translation table in your site. This problem is not causing a problem running the site right now, but can become a critical issue in the future. WPML support team knows how to fix it. Please add a message in the relevant support thread and we’ll fix it for you."
I understand the issue you're having. Would you please follow the instructions mentioned in the ticket below and check if that helps to solve the issue?