To resolve this issue, stop the active tasks and re-start them as a different user. This can be accomplished by navigating to Process Monitoring and Filtering for the User in question. This should show all active tasks for this user which will need to be restarted.
The functionality "Take over Task" can be utilized as well:
Use this option to carry out operations and receive notifications on behalf of another user. This can be useful to act as deputy and receive notifications in cases of leaves or for system administrators to repair processes on behalf of operators.
In addition to adding transparency, transferring the ownership of tasks is useful in various ways.
If your system has been configured so, the owner of a task is also the receiver of the notifications that result from processing that task. If the owner is absent, it is possible to transfer the ownership to another user who will then receive the notifications.
When processing a task goes wrong and troubleshooting does not help, your system administrator can probably help and will take the ownership of the task to repair it.
This option is not available either in client 0 or for tasks of type JOBD (remote jobs).