Hello,
there might be more reasons why the client cannot connect. The most likely is that some of the VPN ports are blocked. MacOS and iOS SecureLine uses Cisco IPSec protocol (ports 50, 51, 500, 4500), Android and Windows uses OpenVPN. The other reason can be a device configuration, this should not be an issue on iPhone but we see it sometimes on macOS. Generally it works better if the macOS SecureLine application is installed from the AppStore on macOS since we can use IKEv2+PSK authentication. The license is compatible for both ways of the installation.
To investigate more on our side, we would need a support package (see Help menu of the application). Since the support package contains a sensitive data like your license, please open the support request.
If you would like to verify that the issue is not on your network, you could try to connect at some public place like KFC, McDonalds, Starbucks.
Best Regards,
Martin