Unassign Agent Step
The Unassign agent step removes a particular assignment from the current dialog. It is available only in For dialogs automations.
Identify The Assignment
Open the step on the workflow. Select an agent in Agent and select Primary or Background in Agent role.

The step removes the assignment only when the selected role is currently occupied by the selected agent. It does not remove a different agent in that role. If the required assignment no longer exists, the step changes nothing and continues through Next.
The list may show only active agents. A previously saved step still refers to its selected agent; if that agent no longer exists in the project, fix the step before publication.
Check The Result
Execution requires a current dialog. After a test run, open the dialog information and confirm that the intended role was removed while the second assignment, if present, remained unchanged.