It is important to understand the behavior of the Meraki AP when it is unable to obtain a DHCP lease. This is especially true when the AP is connected to a LAN with other DHCP clients.
If the access point detects an Ethernet link and does not have an assigned IP address, the access point will attempt to obtain an IP address via DHCP. While waiting on a DHCP address, if the AP receives a DHCP DISCOVER from another DHCP client, it will assign a DHCP lease to that device using the Meraki NAT mode IP address range. This is for management purposes allowing the device to connect to my.meraki.com. In the case where the AP is a repeater and wired clients is enabled an IP address based on the settings for wired clients in Dashboard will be assigned.
Once the AP receives a DHCP lease from a DHCP server it flags the interface as connected to the LAN. At this point the interface will no longer respond to DHCP requests from DHCP clients.
If the APs DHCP lease expires, the AP will again attempt to obtain an IP address via DHCP. However it will no longer respond to DHCP DISCOVER's sent from DHCP clients on the connected LAN unless specified by wired client settings in Dashboard.