EventListener is not firing on assignment event

I am using Spring Boot event listeners to catch task events. The events fire when create and complete events occur, but they do not fire when assignment happens. Why am I not seeing the additional events?

I did some testing. When I manually claim a task the event listener fires. It does not fire in the following case. Before a user task, I have a service task that calculates the assignees for the next user task. The assignees’ list is set to a variable, which is then picked in the user task assignee field. In this case, the assignee event is not fired.