I had the same problem in the status informed ok "green", when I went to check in the event logs, Event type informed that: "Unable to contact domain controller " alternating between "Connected to Domain Controller" .
To solve this I checked that in the "domain admin" field I didn't need to inform the domain followed by the \
Put only the domain user name.![domainname.JPG domainname.JPG](https://community.meraki.com/t5/image/serverpage/image-id/20923i4E5206C2426A8B36/image-size/large?v=v2&px=999)
![domainname1.JPG domainname1.JPG](https://community.meraki.com/t5/image/serverpage/image-id/20924i7F6BFD095E8419B0/image-size/large?v=v2&px=999)
Júlio César de Sousa Leal