Tunnel is in NAT mode. I can change it to route mode if that helps, but does not explain the issue why I CAN access the mgmt console at the VPN IP but CANT access the vpn_ip:81

TL-R600VPN has a virtual server running on port 81 This virtual server port is correctly accessed over the https://WAN_IP:81 The management interface is accessed correctly over https://WAN_IP LAN...