@victor
You have a ARP problem. If I understand you right basically what is happening is that your firewall has a public IP on eth2, you did not specify but I guess that it's another prefix different that 41.x.x186/29.
When someone in the internet ask for your server (41.x.x.186) ARP must be resolved and your public interface on your firewall (eth2) doesn't know how to resolve it. Same happens when you set up a manual NAT with a different IP of the wan interface of your firewall.
You could try to sort this out by setting a Proxy ARP entry: When someone ask about 41.x.x.186 reply with eth2 MAC Address. After that maybe you will have to solve some default route issues with PBR.
Hope it helps
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