The idea with disabling DPNP on harvesters is to prevent them from meddling with the network and node, right?
So is it okay to have 8444 open while DPNP is disabled? Or is that not feasible.
EDIT
For now I’ve disabled port 8444. However- I have another bizarre issue. I can’t for the life of me connect to the harvesters via port 8447. Is there a specific local port i need to point to?
My node server’s port 8447 is fine.
With DPNP, I assume you mean uPnP? 
You should disable uPnP on all but one machine in your network because each machine will tell the router: “I’m here! Yoo-hoo! Open 8444 for me please!”.
I don’t know if uPnP advertises multiple times when the app is open but if not then the last machine you start the Chia app on will get it, but I assume it might re-advertise.
Why do you want other ports open? As far as I know, other ports are not at all used by the Chia network.
8447 and 8448 is what a harvester machine uses to communicate with the node machine.
The node machine has 8447 open so it’s able to receive info from the harvesters about the plot… however if the harvester can’t receive inbound info on 8447 then it means a challenge / winning plot won’t get tested.
Ah… sorry about that, I have not investigated full harvester mode.
Anyway, for port opening on the internal network check firewalls on all machines, bit hard to give generic advice for that as it depends on OS, firewalls, possibly anti-virus, maybe even router/network setup.
Check the logs and the docs as well?