As alterações feitas com firewall-cmd só são persistentes quando você (também) as torna persistentes com --permanent ...
--permanent
The permanent option--permanentcan be used to set options permanently. These changes are not effective immediately, only after service restart/reload or system reboot. Without the--permanentoption, a change will only be part of the runtime configuration.
...
If you want to make a change in runtime and permanent configuration, use the same call with and without the--permanentoption.