[Mashiro]

You probably just blocked a port that is needed for OGP or whatever by removing ports from firewalld. You can do what you desire to do. I have no idea about OGP or how it works.

However and advice from me to you. Learn how to use and configure firewalls like iptables, firewalld or ufw. ufw is a simple frontend for iptables usually used on Ubuntu but can be installed everywhere if really needed. Firewalld is the default firewall of RHEL and RHEL based Linux distributions.