This issue occurs due to a race condition between two independent Automatic Call Distribution (ACD) systems: one in Genesys Cloud and one in Salesforce.

When an agent closes a Salesforce work item, their status briefly changes to On Queue in Genesys Cloud. Shortly afterward, Genesys Cloud updates the status to Busy. However, if Salesforce assigns a new work item during this short window, approximately 60 milliseconds, the Genesys Cloud Assignment Service may detect the agent as available. It can then begin routing a new interaction before the Busy status fully takes effect.

Because the External Routing package is unmanaged, customers can modify how Salesforce routes the work items. The recommended solutions are:

• Implement the After Conversation Work (ACW) time in Salesforce with a minimum 10-second delay between work assignments. This buffer allows presence updates to fully process and significantly reduces the likelihood of simultaneous routing from both systems.
• Use a single routing engine to push work to agents, either Genesys Cloud or Salesforce, rather than allowing both systems to independently assign work.

For more information, see About Genesys Cloud for Salesforce.