First thing to check is the external IP address. If you google “my ip address”, the IP address shown in your search results should match the IP address reported under the Internet section of the Status page on the router management console.
And, if you have a dynamic IP address from your ISP (most likely), it’s best to set up a Dynamic DNS and use the domain name instead of IP address to access the server. While your ISP assigned IP address may not change very often, it does change in some situations. And you don’t want to reconfigure your VPN server every time the IP address changes.
Let us know if this is not familiar to you. We’ll create some tutorials to guide users new to VPN.