Cannot enable inbound HTTP traffic to my droplet

Hi,

Recently I attached a new domain to my droplet (currently there are two attached). Since then, I cannot reach my droplet through HTTP requests on port 80, the result is always 404 not found.

I tried everything: rules in iptables, setup a firewall in digital ocean UI with enabling rule for HTTP/S.

I tried with nginx, python SimpleHTTPServer module, none of them are reachable.

I cannot tell if the problem arose due to my new domain or not (which BTW has A, CNAME and NS entries), but the SSH(22), K3S(6443) and TCP(8000) ports work, the latter two after I added a rule for them in iptables and firewall.

Probably there’s something wrong with my setup (and not DO’s fault), but this is getting really frustrating because it completely blocks me (cannot create new certificates, cannot test, etc.).

Does anyone have any idea what could have gone wrong? The system inside the droplet is Ubuntu 18.04.1LTS, Linux 4.15.0-88-generic #88-Ubuntu SMP Tue Feb 11 20:11:34 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux.

Thank you! Alex