CC2531: Coordinator Radio Stops Responding to Messages

Hi,

I am using a custom application that runs on top of Z-Stack 2.5.1a. It runs on a CC2531, that uses a CC2591 LNA/PA. Occasionally the radio stops responding to all incoming messages.

1. Our system periodically sends 4-6 messages. The issue occurs when we are attempting to transmit these messages. 1 or more messages will be successfully delivered before the hang occurs.
2. No messages sent to the radio are acknowledged, including data requests and APS messages. It appears as if the radio never switches back to rx mode.
3. The issue lasts for about 8 seconds, and then the behavior of the coordinator continues as expected.
4. I have tested with a CC2531 without a CC2591 and the issue has yet to occur.

Does this behavior remind anyone of any issues they have seen?

Any suggestions on radio state that can be pulled/examined to help determine what is happening?

Thanks,

Brandon