I merged the other thread you created on this configuration since it stems from the same misconfiguration, most likely.
The decision to perform HTTPS Inspection needs to happens before Access Rules or NAT are applied.
Which means your HTTPS Inspection rules should be created accordingly.
I assume based on your configuration that you're trying to forward connections that occur to the firewall's external IP to the host ACFW-CHKP-BWAPP.
The "certificate' column in the rule would be where you'd configure the private key to use when connecting to ACFW-CHKP-BWAPP.
This means your HTTPS Inspection rule should have "any" as the source (not the gateway as shown).
I suspect this will also fix the issue with the NAT rule.