pfSense OpenVPN Site-to-Site

[beshqena87]

I'm building a site-to-site vpn network using pfsense and openvpn using this guide
click here

topology is as follows:

site 1: private property, server is located behind ISP modem and property owner's router. there is no static external IP but, port forwarding is set up, so its pointing towards the server.
server has two VMWare machines, one containing specific software and the second one, a pfsense box serving as openvpn server. I've set up dynamic DNS pointing to the external IP of the site and checking an external IP of the site using browsers and pinging our dynamic domain name gives same IP address.

openvpn server has one WAN and one LAN virtual adapters. WAN virtual adapter has static IP and port forwarding is set up to direct any port 1194 port traffic to it. LAN adapter is used to communicate with other virtual machine.

site 2: office in the same city, network is managed by pfsense box with two network cards, one serving as WAN and one serving as LAN. this box is behind ISP's modem and company owner's router as well and serves as openvpn client, to connect to the server.

site 3: basic network topology is the same, only difference is that, we're using mikrotik 4G router, instead of ISP's modem and there's nothing inbetween it and pfsense box and its located in another city.

site 4: same as site 3.

now, the problem I'm having. setup on server side and client side is done according to that guide. but when trying to connect to server from site 1, openvpn service is unable to connect to server side.

now, I've done everything according to that guide, but might be missing something and need advise.

thanks in advance O:)