I have a java process that executes some rules on the iptables.

iptables -t nat -A SN-Forwarding -p tcp --dport xxxxx -j DNAT --to xxx.xxx.x.xxx:80
iptables -A SN-Forwarding -p tcp -d xxx.xxx.x.xxx --dport 80 -j ACCEPT

These rules appear in the iptables correctly when I do

iptables -t nat --list --line-numbers
6 DNAT tcp -- anywhere anywhere tcp dpt:xxxxx to:xxx.xxx.x.xxx:80

and the port forwarding works properly.

but when I enable the firewall on my redhat vm, these rules are no longer available, disappear and the port forwarding does not work.
and when I try to execute this rule
iptables -t nat -A SN-Forwarding -p tcp --dport xxxxx -j DNAT --to xxx.xxx.x.xxx:80
manually I get iptables: No chain/target/match by that name

Why are the rules getting deleted when the firewall is enabled, when I disabe the rules appear again.

Thanks