Struggling to forward a localhost port to another port on localhost

Help
1

I have a dev server that runs with https on port 3000 and I need to access it via port 443 for CORS reasons.

I’ve tried the following configuration

  networking.nat = {
    enable = true;
    enableIPv6 = true;
    internalInterfaces = ["lo"];
    externalInterface = "enp27s0";
    forwardPorts = [
      { proto = "tcp"; sourcePort = 443; destination = "::1:3000"; }
    ];
  };

but whatever I try, I get the following error from curl:

curl -k https://devserver.myworkdomain.com -v
*   Trying [::1]:443...
* connect to ::1 port 443 failed: Connection refused
*   Trying 127.0.0.1:443...
* connect to 127.0.0.1 port 443 failed: Connection refused
* Failed to connect to devserver.myworkdomain.com port 443 after 0 ms: Couldn't connect to server
* Closing connection 0
curl: (7) Failed to connect to devserver.myworkdomain.com port 443 after 0 ms: Couldn't connect to server

I have dnsmasq setup to resolve the workdomain to localhost ipv4 and v6.

I have also set the following sysctl setting:

  boot.kernel.sysctl = {
    "net.ipv4.conf.lo.route_localnet" = true;
  };

If I do the same curl command but with :3000 on the end of the domain, I get a proper response so I’m pretty sure it’s just not forwarding the port properly.

Update
I can see the port forward in the iptables output and I think that should be working but I still get the same error

Chain nixos-nat-pre (1 references)
target     prot opt source               destination         
DNAT       tcp  --  anywhere             anywhere             tcp dpt:https to:127.0.0.1:3000

curling 127.0.0.1:3000 directly works and I get the proper response