It looks like WPML could be conflicting with another 3rd party plugin.
Please backup and try the following steps and see if it helps:
1. Disable all the plugins except the WPML related ones from your WordPress Dashboard > Plugins and see if the issue is gone, if so, activate one plugin at a time until the culprit one is found.
2. Temporary change to a default WordPress theme such as the ‘TwentySeventeen’ theme from your WordPress Dashboard > Appearance > Themes menu.
If the issue persists, I would need to take a closer look at your site. So I would need to request temporary access (WP-Admin and FTP) preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed
Your following answer will be private, which means only you and I have access to it.
✙ I would need your permission to de-activate and re-activate Plugins and the Theme and to change configurations on the site if required. This is also a reason the backup is critical.
Thanks for your reply. I can see the issue now. Could you share FTP access here so that I can escalate this further to our 2nd Tier Support so that we can investigate this further?
Thanks for your reply. Can I have your permission to perform another plugin deactivation and switch to a different theme? Also, I need your permission to install the Query Monitor plugin as requested by our 2nd Tier Support.
If you agree, please perform a full backup and notify me.
Thanks for your patience. Your website is still in the queue for review by our 2nd Tier Support team. I’ll get back to you as soon as I have their feedback.
Thanks for your patience. Our 2nd Tier Support checked, and they suspected some code is being injected into our plugin core that causes the issue.
I regret any inconvenience caused, but to proceed with further troubleshooting, I kindly ask for a snapshot of the site. Alternatively, with your permission, I can create one myself. For this purpose, I typically recommend using the free plugin "Duplicator." If you're already familiar with Duplicator (https://wordpress.org/plugins/duplicator/), please skip the following steps and simply send me the archive file you downloaded.
To guide you further, please adhere to these instructions:
1. View the Duplicator instructions video: hidden link
3. If the archive file exceeds 400MB, please use Duplicator's file filters to exclude cache, wp-uploads directory, media, and archive files.
Once you have the archive file ready, kindly share the link with us. You can utilize platforms like Google Drive, Dropbox, or similar for file sharing, as the snapshot file might be large.
Please note that your next reply will be private, visible only to you and me. You can paste the file link there. Rest assured that once the issue is resolved, I will delete the local site.
Thanks for your patience. I apologize for the delay due to the weekends. I'm working on the copy now and I will come back to you if I need anything further.