CID not being set on IVR call to Custom Trunk

I’ve got an Misc Application that defines a feature code to execute an IVR - in other words, an outbound IVR. The IVR has an entry to pass control to a Custom Trunk that dials a SIP number.

The Trunk has a CID specified with Force Trunk CID, but this information ignored when the call is made, and the CID info is from the calling extension.

Bug? Or just something to work around?