USG20W-VPN - Where is the one-to-many NAT rule?

Hello community;

I've setup this firewall as a trivial home router, allocating all ports to the same interface and using them as a switch, and the WAN port connected to my ISP. Straightforward and no hassles but I noticed that I couldn't find any NAT or firewall rule that would allow my LAN to access the internet despite being able to do so.

I've looked under 'configuration → netwotk → NAT' and 'configuration → security policy → policy control' as the most likely places to hold such rule but didn't find any. Looked at all options afterwards but still didn't find it.

Exporting running-config and peeking into it also led me nowhere.

Am I missing something or is this rule sort of hardcoded and not configurable?
Running firmware V5.43(ABAR.0)

—
Paulo