You should go here (https://wpml.org/account/sites/) > remove the current key > generate a new key that will NOT be set as dev site > copy the new key > go to your website's backend > Plugins > Add new > Commercial > unregister WPML from the dev key and register WPML with the new key.
That should resolve this. If it doesn't, please make sure that you clear all the site + server caching/CDN (if you don't have access to clearing server caching, please get in touch with the hosting support team as they might be the only ones that can do that for you).
Please let me know how things go and if you still need help.
