Unable to resolve DNS from with a droplet created via terraform

I’ve created a droplet and firewall config (using terraform) from the docker-18-04 and docker-20-04 images and I am unable to perform any DNS resolution from within these hosts. I’ve opened 53/tcp and 53/udp outgoing in the DO firewall, and tried opening them using UFW on the host as well just in case, with no luck. What else would interfere with DNS resolution from within a newly created droplet?

Just in case it helps, this is what the relevant part of the config looks like in terraform:

resource "digitalocean_droplet" "cafe" {
  image = "docker-20-04"
  name = "cafe"
  region = "sfo2"
  size = "s-2vcpu-4gb"
  private_networking = false
  monitoring = true
  ssh_keys = [
    digitalocean_ssh_key.hal.fingerprint
  ]
}

resource "digitalocean_firewall" "cafe" {
  name = "cafe"
  droplet_ids = [ digitalocean_droplet.cafe.id ]
  inbound_rule {
      protocol = "tcp"
      port_range = "22"
      source_addresses = var.vpn_source_addrs
  }
  inbound_rule {
      protocol = "tcp"
      port_range = "443"
  }
  inbound_rule {
    protocol = "icmp"
  }
  outbound_rule {
    protocol = "tcp"
    port_range = "53"
  }
  outbound_rule {
    protocol = "udp"
    port_range = "53"
  }
  outbound_rule {
    protocol = "icmp"
  }
}