[Solved] OpenVPN server not reachable from WAN on TP

Hello everyone,

I am using OpenWrt 22.03.5 on a TP-Link Archer MR200 version 1 hardware. The targets are:

Images for below description:

I followed these instructions [OpenWrt Wiki] OpenVPN server and created 5 users with tls-crypt-v2 and one user with tls-crypt (v1) for use in the ASUS router client. Additionally, i created the openVPNserver interface and the relevant firewall zone vpn_server to accept wan.

The problem is that there is no connection from WAN area and the result is the repetition of the DISCONNECTED event, exactly the same from whatever device/ WAN I tried it. The server's IPV4 address resolves OK (using ddns).

The IPV4 routing table seems to be OK (see image).

The directions for this android modem from [OpenWrt Wiki] TP-Link Archer MR200 v1 do mention: " If you need to connect to your router through wan or to do wan port forwarding, instead of relying on the LTE modem's internal DHCP server, the router's usb0 IP address must be manually set to 192.168.225.100 (and of course with the default gateway and possibly DNS address of 192.168.225.1). " When I use static IP address for the usb0 interface by filling everything needed (see above image), then, surprisingly, I do not have DNS working and cannot resolve any address, even if I fill the relevant filed with 8.8.8.8, thus no browsing possible.

Any ideas on how to resolve the above issues and make the OpenVPN server working? Many thanks in advance for your help.