Why doesn't openvpn work over the wire?

Question

openvpn

Raised my own openvpn server on ubuntu 16.04. Such a problem is that there are two computers in LAN: one via Wi-Fi, the other via twisted pair. Which is ok on wi-fi, openvpn works, visits blocked sites. Which is connected by wire - openvpn is connected, the IP address is replaced, dns too. But he accesses blocked sites as if from a Russian IP, all blockings are in effect. And the computers changed places, i.e. put the first wire, the second wi-fi. The problem is with the wire connection.
I tried forwarding to open ports on the router (züksel), firewalls and antiviruses are not worth it.
The same problem was with connecting l2tp + ipsec vpn, but there the problem was solved by disabling ipv6 in the settings. Here it was not decided.

Answer 1

Solved, added
push "block-outside-dns" on the server