If a Service Type is attached to a classic workflow task which in turn belongs to a category and this category is attached to a Change Order, there is potential for service type to start as soon as the Change Order is saved.
As an example if a category has 4 workflow tasks and the third task (Sequence 30) has a Service Type attached.
This is the workflow detail. Service Type "04hr resolution" is attached here.
The expectation of creating a new Change Order from this category would be that the Service Type starts as soon as the workflow task (Sequence 30) becomes "Pending" and not when it is still in a "Wait" state.
By default, the Service Type becomes active when the status of the workflow task changes to "Pending" and not when it is in a "Wait" state.
More precisely, the Service Type will become active as soon as the workflow task changes to a status which allows you to update the task.
Check the Task Status Detail of the status "Wait".
If the attribute "Allow Task Update" is set to "No" (this is the default), then the Service Type starts, when the status changes to "Pending".
But if it is set to "Yes", then the Service Type starts immediately.