The container doesn't have access to the internet and thus is not able to verify the license key. Your options are to setup the container to have access to the internet, introduce a licensing proxy server, or introduce an on premise license server.
This can be done with enabling routing within the network so that the AoIP network can access the internet. This would be the case if the Container server has only one network interface. This will be required if needing to use WebRTC technology for remote audio contribution.
Another option is to configure the container with access to a second network interface if the Container server has multiple NICs and one is dedicated to the AoIP island and another is connected to WAN. This can be done by modifications to container, for example configuring the docker-compose file with a second interface.
A PC (Liniux or Windows) with network interfaces connected to the AoIP network and the office network can have a proxy service installed. The container will need to be pointed to the IP of the proxy server.
In some workflows an on premise license server will need to be installed but is the most difficult to work with. This requires a machine to be installed with the needed software and each time a license is generated or renewed a process of entering the keys into the on premise license server needs to be carried out.
This indicates the license has been registered and is in use. The license key can not be used until the registered user releases the license key. In some cases this could happen if a container is torn down, replaced, or otherwise goes offline without properly releasing the licenses associated with it. Bring that previous container up and release the licenses or call Telos Support for further assistance.