Hi  @dinosaurscuba 

Thanks for posting here.

The above is an explanation of the “disconnected” status.

Since the device’s network was not affected during the disconnect, the issue likely lies in communication between the device and the OC400 (purely internal).

You may troubleshoot from the OC400 end, for example, replace the OC400's network cable, relocate the OC400, etc.

Hi  @dinosaurscuba 

Thanks for the reply.

For this type of issue, the first step is to verify connectivity to the OC400. To pinpoint the exact cause, it’s essential to analyze it alongside your network topology and the actual environment. 

We recommend submitting a support ticket via email for efficient assistance.
Please include the following information in the email:
1. This Forum ID 856810;
2. your community nickname;
3. The topology of the network
4. The config file of the controller.

  @dinosaurscuba 

Did you ever find out what was causing this?  I have an OC300 and experienced something similar.  Here is the thread.