This alarm is fired if a preferred node has been set in Windows Server Failover Cluster Manager, and a Cluster component is found to run on another non-preferred node. If you do not configure the preferred node then no alarm will be fired.
If desired, move the Cluster component back to the preferred node as set in WSFC Manager or in the SSMS Availability Group configuration.
On the Cluster dashboard view we may also show the following messages with the Group info:
1. "Warning: No preferred server has been set."
2. "Warning: Not running on preferred server."
This Alarm is only informational and not an indication of a error, but of a possible configuration that may not be optimal depending on the available node resources. It is not related the Cluster Type (Active/Active, Active/Passive, etc...)