VPN not resolving dns names


I have a problem that when I setup a VPN on vpnVM and connect to it.
on vpnVM I can ping address (example.com)
on appVM I cannot access address (example.com) but I can access it using its IP.
I understand that DNS is not resolving name correctly but I do not understand Qubes network enough to fix this.
Can anyone advise please.

are you using any special way (vpn, tor, etc) to connect?

I am using standard openVPN connection set up from network manager.