As mentioned by GIdenJoe, you need to consider site-to-site traffic as a separate ZONE.  Generally, site-to-site VPN rules are applied organization-wide, across all VPN-enabled MX devices.  VPN Firewall Rule Considerations  When configuring VPN firewall rules, it's important to remember that traffic should be blocked as close as possible to the originating client device. This reduces traffic in the VPN tunnel and results in better network performance. Therefore, site-to-site firewall rules are only applied to outbound traffic. Thus, the MX cannot block VPN traffic initiated by IPsec VPN peers.        https://documentation.meraki.com/MX/Design_and_Configure/Configuration_Guides/Site-to-site_VPN/Site-to-site_VPN_Firewall_Rule_Behavior     Note - Site-to-Site Firewall Rules Behavior when Group Policy is Configured    If Site to Site Outbound Firewall Rule allows and Group Policy L3 denies, traffic will be denied.    If Site to Site Outbound Firewall Rule denies and Group Policy L3 allows, traffic will be denied.    If Site to Site Outbound Firewall Rule denies and Group Policy whitelisted preset is configured, traffic will be denied.   
						
					
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