Nginx reverse proxy stopped working after applying upgrade from Rocky 8.4 to Rocky 8.8

After upgrading my Rocky Linux from 8.4 to 8.8, my nginx 1.1.14 1-9 reverse proxy session doesn’t seem to operate as expected anymore. Instead I see a lot of FIN ACK packets (tcpdump) when loading my Graylog landing page such that it shows the below message. But when I directly go to my Graylog installation on port 9000 it loads fine.

Before the upgrade, I tested this and it worked fine. After the upgrade it no longer works. I know the upgrade had some security policy (selinux) upgrade as well. Any idea where I could be going wrong?

It turns out that upgrade from 8.4 to 8.8 changes the security policy of the firewall. Maybe. I am yet to replicate this. Port 80 in my system was closed off after my upgrade. I had to add port 80 again in the firewall.

I will replicate this with production system update.