Good day

Have not been able to establish VPN connection between 2 devices with the following setup:

Remote site with Festa Festa FR365 v1.0

Modem to Fiber optic to ISP with dynamic IP and DDNS is setup. So it is reachable by a domain name

Modem is setup with DMZ to the router

Have been able to connect through any port with port forwarding to any equipment on the network.

HQ Same setup but with Festa FR205 v1.0

Settings: router to modem is dinamic IP instead of static IP. 

Same ISP for each site for VPN setup.

Tried with Autoconfiguration and manual configuration. 

Have not configures Client-to-VPN settings.

Important to establish Site-to-Site connection and disable all, about 20, port forwardings at each site that are configured in the modem and router.

Appreciate any feedback what could be wrong with my setup.