Port 80 not accessible outside of the VPC network, 443 works

I have an old droplet, which is not part of any VPC networks (those were’t a thing 9 years ago when the droplet was created), and I can successfully access port 80 on it. The iptables rules are there in place, nginx is up&running, so far so good.

However, I wanted to make it part of a VPC network, and since only new droplets can be added to a VPC network, I cloned the old one.

So far so good, however once I booted the cloned droplet, and started running some tests, I noticed I was not able to access port 80 outside of the VPC network. The iptables rules, are the same, nginx is running as expected, basically there configuration is the same as on the old server.

Port 80 is accessible from other droplets in the same VPC network, and port 443 is accessible from anywhere, so it seems that some networking layer above my droplets are rejecting the traffic coming from the outside world.

I don’t have any firewall defined on the DigitalOcean portal, I only have the ones that come with the Ubuntu server.

What could be the problem?