UCX STREAMS

I have written a UCX based USB Host Controller driver. It supports the Capability GUID_USB_CAPABILITY_STATIC_STREAMS and GUID_USB_CAPABILITY_DEVICE_CONNECTION_SUPER_SPEED_COMPATIBLE

The driver loads correctly and begins working, the Microsoft USB Hub 3.0 driver is attached as expected. All devices work fine. Except…

When a USB 3.0 (USB Attached SCSI) drive is attached, the Microsoft USB Hub driver does not select the UASP Interface. It assigns a USB Hardware id with a protocol of 50, instead of 68 as in the UAS interface endpoints.

I can see the USB Hub driver request the Device and full configuration descriptors for the device and i can see the UAS interface and endpoints is part of the Configuration Descriptor.

My Question is, how does the Microsoft USB 3.0 Hub driver determine UAS is supported? I cant see what im missing. i was expecting with the setup as above that the hub driver would just select the UASP interface automatically (and populate the PnP Hardware Ids correctly)