firewalld not working after reboot

Hi, I have an issue where, after a system reboot (Oracle Linux 7), communications to the node are not working correctly. If i stop and start (often a restart doesn't work) the firewalld service the network will work correctly. While things were broken I did a: 'firewall-cmd --list-all' and noticed that two of the interfaces were missing. Where can I look to determine what may be going wrong when firewalld starts after a reboot? Thanks, Rob