I’m posting this here as this should be public, as this is the second time running into this issue. And, I do not find Meraki Support to be willing to even give details to why this issue happens.
I moved two wireless clients into the “Blocked” Policy. And, clicked on Save. Within 10 minutes all other clients that had Group Policies assigned lost their correct Policy. They still showed as having a Policy assigned, but, the IP showing in the dashboard and assigned to the Client was not correct for the VLAN they should be assigned to. We use Group Polices on wireless devices to assign VLANs. I had to select each Device and just reapply the Policy—without changing anything for the Policy to have it *apply* again to the client device.