Update, we are told (Meraki TAC) this relates to a VLAN tag on the WAN configuration. Apparently an old issue seen strips the VLAN tag from the port config. We are seeing this. When you first connect a unit to the WAN and it connects to the dashboard, then tries to download firmware, if you look at the Uplink config in the dashboard, the dashboard has stripped the VLAN tag from the link. We have been told to add this to the dashboard before the next reload/download happens and it should go fine. What appears to be happening is the VLAN tag gets stripped, the MX can no longer see the dashboard and it recovers itself by rolling back.
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