For what its worth, I am using an older version of the SDK but there is a comment in the rx_isr.c file where it handles the Channel Status interrupt. It reads...
/*==================================================
* Channel status data valid changed
* This interrupt is not triggered for HBR audio
* and the CS bits are always invalid for HBR
*=================================================*/
I too have experienced the same problems with Channel Status data and HBR audio. So I don't depend on this data when receiving HBR audio packets.
Regards,
BrianP