FlightXML trying to upsert with SetAlert

I’m trying to upsert registered alerts, by supplying ident and -1 for alert_id.

Expected:
If the alert already exists, return the existing alert_id. Otherwise, create new alert and return new alert_id.

Actual:
Returns the error message
“APPFAULT: {alert_id} may only be -1 when ident is specified”

I am supplying ident of the form VOZ1576-1470720949-airline-0329

Please try again after 2016-08-11 00:00 UTC. There should be a change to improve this.