The security appliance at <...> has detected IP conflicts with devices - why?

[DanielOdievich1]

Every month or so I get an email from meraki like that:

The security appliance in the <my>  network has detected IP conflicts with two or more devices.

The IP 192.168.0.239 is claimed by clients with the following MAC addresses: 00:22:3F:FB:A3:E4 00:22:3F:FB:A3:EC
The IP 1.1.1.1 is claimed by clients with the following MAC addresses: 68:3A:1E:32:40:8E 68:3A:1E:32:4C:4C

The message regarding 192.168.0.239 maps via OUI tool https://www.wireshark.org/tools/oui-lookup.html to 00:22:3F Netgear which is two old but good Netgear GS108T switches. Both have DHCP turned on on the device but in Meraki I assign static IP assignments to them and I can both access them via those static IP and see those assignments in Clients page.

The message regarding 1.1.1.1 appears to have 68:3A:1E Cisco Meraki. I can't see those clients in the Clients page

What might be going on? 

[cmr]

It is usually when the device that the endpoints connect to reboots, the devices reconnect and a number of Meraki devices default to IP address 1.1.1.1 and send out a DHCP request.  This gives them a correct IP in your subnet, but the initial moment causes this to happen.  I get it every time I upgrade the MX and MSs in the network and it is from some MRs  I also get it when I upgrade the MRs from some smart lights that also all default to the same IP whilst sending a DHCP request.

I don't find it causes any operational issue, just an annoying alert!