I have a vendor-supplied openvpn config file that works correctly with the openvpn command line client. However, using the same config file with networkmanager-openvpn (the openvpn plugin for Network Manager) results in incorrect / extra routes being added. Those routes direct all traffic over the VPN tunnel, when the config is designed to route only a single IP address over the VPN.
I can't supply the vendor's config file, but I can provide more info if requested.
I tried telling Network Manager to "Ignore automatically obtained routes", but that checkbox did not resolve the issue.