- Plesk Onyx for Linux
Plesk Firewall flushes custom NAT rules that were defined in
Plesk Firewall does not support such customizations as NAT rules. It is not possible to use both Plesk Firewall and custom rules such as NAT.
If it is necessary to use NAT on the server, Plesk Firewall should be disabled in Tools & Settings > Firewall > Disable Firewall Rules Management:
Vote for this feature of creating such rules in Plesk Firewall on User Voice portal.
The top-ranked suggestions are likely to be included in the next versions of Plesk.