Currently, in Service Desk, one of the Stop conditions for the SLA available is 'Assignee : From Unassigned'. While this would work well if the issue was indeed unassigned, in the event that an issue is assigned during creation, it would not be recognized by Service Desk, as the issue was technically never 'Unassigned'.

While this makes sense in logic, it does not work well for users who want the SLA to stop whenever the issue is assigned, even if the issue was assigned during creation.

A possible way to bypass this would be to replace the 'Assignee : From Unassigned' Stop condition to something else (the 'Assignee : Set' which is a Pause condition currently might work well in my opinion).