Restore NordVPN on Ubuntu & Router

I had NordVPN running smoothly on my new Ubuntu laptop for the first few days, but after tweaking some network settings on the machine the VPN refuses to reconnect. I would like someone to:

• diagnose what I changed in Ubuntu’s network stack that is blocking NordVPN,
• put those settings back into a clean, working state (command-line or NetworkManager),
• verify that my home router is forwarding traffic or configured correctly so the VPN handshake is not being blocked, and
• give me a short walkthrough so I understand how to avoid breaking things again.

The job covers both the laptop and the router. We can work over a screen-share or SSH, whichever you prefer, as long as you explain each step. Experience with Ubuntu 22.04, NordVPN CLI/App, iptables or ufw, and basic consumer router admin pages is essential. Once the connection is stable and survives a reboot on both devices, I’ll consider the job done.