"WPML needs to connect to its server to check for new releases and security updates. Something in the network or security settings is preventing this. Please allow outgoing communication to wpml.org to remove this notice."
There's a big chance that what you are seeing is a false-positive that remained in the server caching and the notification will be removed automatically when the cache will automatically clear on its own.
To check if that's a false positive, go to Plugins > Add new > Commercial > click the "check for updates" button and if the page refreshes and WPML is still showing as registered, then yes, that is just a false positive.