Can someone recommend a VPN that lets me open the bitcoin and lightning ports?
Yes, your problem is that Nordvpn does not support port forwarding.
Unfortunately at the current moment we do not offer port forwarding, as multiple customers are using the same servers.
This quote For some sites that support this feature, I did not check that list but you can ask the support team before buying. Find more here --->
https://thatoneprivacysite.net/This is a Youtube Video using ProtonVPN---->
Bitcoin Full Node - How to accept inbound connections using ProtonVPNAirVPN
BolehVPN
Hide.Me
IBVPN
IVPN
NEXTGenVPN
oVPN.to
Private Internet Access
Proxy.sh
TorGuard
ZorroVPN