So I managed to smash a few buttons randomly again, and get this solved.
There are a few things to be aware of:
Oracle doesn’t like ufw. So I disabled it and uninstalled it. Having ufw installed may result in bad stuff. Link
I decided to flush all rules in ip-tables to start on a clean slate: sudo iptables -F
While I’m at it, I’ve changed ip-tables to allow ALL. THE. INBOUND. TRAFFIC: sudo iptables -I INPUT -j ACCEPT
One last thing, I’ve changed the state of the firewall to go from stateful to stateless, still with no restrictions on the ingress / egress traffic.
This is, of course, not a recommended setup for a host to be used in production or to have critical data, but it gave me a host in a working state that I can work with.