When I view my unattended computers after logging into meetinglab.zoho.com, I have noticed three different statuses, one of which (yellow) I cannot understand. Is there documentation explaining each of these?

1. Green circle - Awake and available for remote session.
2. Grey circle - Unavailable. I have seen this when the remote computer is asleep or turned off.
3. Yellow circle - Unknown. (See image below) The 'Connect' button is available. When I try to connect, I receive a message that says, "Waiting for remote computer to respond..." which ultimately times out.
4. Are there others?

Robert