@mseedii,

You may need to open specific ports for your client to successfully connect to your VPN server - what service are you using?

I would also check to see if uPnP is enabled or disabled, as this is the service that will automatically open and close ports based on active connections. If the service is disabled, then the connection cannot pass through as the port is not being opened automatically. 

In more recent devices, it is not uncommon to see the setting disabled by default.

  @mseedii,

Yes, most services use specific ports for their connections, such as Cisco's Anyconnect VPN server requiring port 443 to be opened. Depending on what VPN service you are using the required ports may be different.

You can see the steps in this guide to manually open a port on your Deco, but I would first recommend seeing if the uPnP setting is enabled or disabled, as this is what most likely made your last router automatically work with the service. You can see where to find the setting in the first screenshots of the FAQ.

How to Set Up Port Forwarding on Deco