Outbound NAT configuration

[stephane.hofman]

Hello,
I'm migrating a Firewall from PFSense to OPNSense.
I have a particular configuration for the WAN interface : I have a public IP address, in a range that is not allowed to acces to Internet (used by the FAI for routing hardware)
So I need config an outbound NAT rule  to another public IP to enable the traffic from the LAN Network. It works.
But with only this, the firewall himself can't access to internet, and can't update or install package.
With PFSense, I have done another outbound NAT rule, from the firewall to the same public IP than the computers. And it worked...
When I do the same thing with OPNSense, the firewall can access to Internet, but all the NATed service are not accessible anymore from the outside... Any idea, what's going on ?