SLA stop trigger "Assignee: From Unassigned" continues when issue are submitted via JIRA

Problem:

When an agent submit an issue on behalf of the customer via JIRA and assigns themselves or another agent to the ticket upon creation, the SLA for Service Desk continues to tick even though Assignee: From Unassigned is set to stop the given SLA.

I suspect this is because the Issue Assigned event is never triggered when the issue is created with an assignee.