Hello,
I have replicated your configuration, but the tunnel established and devices were successfully able to ping each other, server was reachable from the client as well, thus no issues with the configuration, that is, if certificate options were removed intentionally from provided configurations.
What could be checked are the firewall settings on the server's side. Login to your RUT955, navigate to Network -> Firewall -> General settings. Make sure there is a separate zone for OpenVPN. Also, check the settings for this zone: it must accept input and output traffic, have Masquerading enabled and also allow forwarding to/from LAN zone.
Switch to Traffic rules page, there should be a rule Allow-openvpn-traffic enabled to accept traffic on 1196 port. Though, without it, the tunnel would not be established at all.
You can also try lowering tunnel's MTU value by adding a following push option to either server's or client's configuration:
Otherwise, have you tried disabling firewall on the client's side, to check, if it does not interfere with the communication?
Best regards,
