Root Cause: The KEEP_ALIVE variable is not correctly used by the Agent, which doesn't reconnect to the second Automation Engine directly.
Update to a fix version listed below or a newer version if available.
Fix Status: In Progress
Automation Engine 12.2.0 - Planned release date: 2018-06-19
Automation Engine 12.1.1 - Available
Automation Engine 12.0.4 - Available
Completely restart the Windows Agent.