The client list is populated by devices that have sent internet destined traffic that exits the WAN port. A client will only appear in the list once it has passed Internet traffic. If a device, such as a LAN printer, does not pass any Internet traffic, then it will not appear in the list. https://documentation.meraki.com/General_Administration/Cross-Platform_Content/Clients_Usage_Page_Overview#Clients_Overview I've also occasionally seen small delays in clients showing up in the list (1-2mins) after coming online.
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