I have recently installed a VR400 router as a replacement for my old router that stopped working.  It is connected to the internet via the VDSL modem.

On my network I have a Raspberry pi running pihole and pivpn (as a VPN server).  The pihole also acts as the DHCP server.

In addition, I have three other routers (all different makes), all configured as access points.  They are connected to the VR400 by ethernet (using powerline adapters).

My configuration is as follows:

VR400: IP address 192.168.0.1  DHCP disabled. Port forwarding of port 12345 to 192.168.0.3 port 12345  for TCP and UDP (from the Virtual Servers admin page).

Pihole & pivpn: 192.168.0.3

Access point 1: 192.168.0.4 DHCP disabled

Access point 2: 192.168.0.5 DHCP disabled

Access point 3: 192.168.0.6 DHCP disabled

All of this was working prior to replacing my main router.

My problem is connecting to the VPN server – I am running Wireguard on an Android phone + tablets.

From the external internet, I can connect successfully.

From the wireless on the VR400, I can connect successfully.

I cannot connect wirelessly from any of the three access points.  All work fine with the VPN switched off. Looking at the Wireguard logs, it says that the handshake did not complete after 5 seconds, retrying.

To my mind this points to a setting in the VR400 somewhere, but I can’t find it.

Does anyone have any suggestions please?