Hello,
I would recommend to deactivate all plugins first. Maybe one of them interferes with the URL handling in WordPress. Because the message is generated by WordPress before the actual request to the URL.
Please deactivate all third-party plugins and activate only the theme-required plugins on your site. Then, check if the issue is resolved. If the issue is fixed, reactivate the third-party plugins one by one to identify which plugin is causing the problem.
If the issue persists, then please remain all the third party plugins deactivated on your site and share your site WP Admin URL and Credentials, under the private content area of this topic, so that I can further look into it for you on your site and help you out.
Best Regards,
.
