Unable to block Inter-VLAN Traffic

[krazeh]

@cliffordanup

config zone
        option name 'lan'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option network 'lan LAN4_Venu LAN3_Guest'
        option forward 'ACCEPT'

You've got all LANs in one firewall zone here with an accept rule for forwarding. That's why they can all talk to each other.