Sorry for the delayed response here due to the weekends.
I tried to replicate the issue on a local site but I was unable to do so. Will it be possible for you to setup a staging/test clone site of the site on the same server and share the credentials of the test site with us so that we can troubleshoot the issue further there?
I have enabled a private reply for you to share the details safely.
Thanks for your reply. The link I had provided is the staging site so hopefully you should be able to use the info shared previously. Let me know if you have any issues.
I tested the issue further on the site you provided during the chat and I see the issue is being caused due to interference of the custom theme on the site with WPML.
As you can see on the site, when you activate a default theme like twenty twenty-three the issue is no longer there. In this case, I recommend you consult with the theme developer/provider and troubleshoot the issue further and contact us again with more insight on the issue if you need further help from our end.