Service Pro assigned but not sent when WO created via API

Using the WOCreate command, we have an app in production that allows users to submit WOs to Corrigo from their mobile. However, if the WO should be sent to a service pro, that doesn't happen. The new WO displays a message "This Work Order is assigned to a Service Pro but is not yet sent" and there is no sent step in the activity log.

Is this a field in the API or a setting in the app? This works from the web form that we have had for years, but not via API. Any help appreciated.