dhcp_dns don't seem to have any effect

[opentokix]

resource "upcloud_network" "private-network" {
  name = "private-network"
  zone = "se-sto1"
  ip_network {
    address = "10.192.168.0/22"
    dhcp = true
    dhcp_default_route = true
    dhcp_dns = ["1.1.1.1", "1.0.0.1"]
    family = "IPv4"
  }
  router = upcloud_router.private-router.id
}

I have created a private network, and a router and get default routs but the dhcp_dns don't seem to be set on the network when I create a machine with a interface on this network.