Hello,
It is not quite clear, which side is the server, which is the client.
In case RUT240 acts as a server, to reach the OpenVPN server's private network from the network1 (client's) side, you would need an additional Push option in server's configuration, to provide with the necessary routes to RUT's LAN, similar to the one below:
- route <network1_LAN_IP> 255.255.255.0
Otherwise, you would need to configure TLS client in the server's configuration, if RUT240 is configured as a client.
You can also check the wiki instructions, provided here.
If the above suggestions do not help, I would like you to attach a troubleshoot file to your question, to review your configuration. Please, replicate the issue, then access router's WebUI, go to System -> Administration -> Troubleshoot section and download troubleshoot file from there.
Best regards,