Ring the bells! We believe we may have found the culprit! Or at least, we have found something that prevents the test project from reproducing the bug. The test project in my post on October 2 uses IP address definition for 2D displays. I revised my project in the following way: 1. Set computer names and a cluster name for the 2 displays I have online 2. Set the cluster name in preferences 3. Define all my 2D displays by computer name instead of IP address I would have never