It must be a Paperless-ngx specific issue. Stopped Homer service available on :8888 and changed Paperless-ngx to be served on :8888 and it still doesn’t work. This rules out firewall and network issues as Homer was accessible on this port.
Nothing in Unifi firewall logs nor Paperless-ngx logs. I’m using standard zones based a firewall rules in Unifi. And I looked through the firewall rules, and I don’t find anything related to port 8000.
Ping and traceroute are both successful. The IP is not the issue (I think), as all other services on the same server are working fine According to unifi firewall logs, nothing gets blocked when I attempt to access Paperless-ngx.
Without having time to test it yet, I think this is the issue.