Programmable XB24C xbee_transparent_serial stops after period of time

I have an application where I have a programmable XB24C ZIGBEE Reg (firmware 4060) sending data with xbee_transparent_serial to a X-stick coordinator (firmware 21A7). The application works great and sends my command data 10 times a second. The problem is that sometimes after about 500 to 1000 packets are sent, I no longer receive more data on the X stick. I can monitor the XB24C through uart and see that it is still performing it’s code properly acting like it is sending data and the xbee_transparent_serial command is still returning a 0 that it was successful.
I can also use the X-stick to remotely send AT commands to the XB24C and they work. I also can request I/O updates with the x-stick to the XB24C and I receive up to date I/O info. But the data packets still show they are being sent but they never show up at the X-stick after.

The extremely odd thing is that sometimes the system will run fine for days (1,000,000+ packets) at a time without skipping a beat. But sometimes (always after powering down and up of the XB24c,) the x-stick receives only between 500 and 1000 packets and then does not receive any more of the data packets.

To get out of the issue I can power down the XB24C for a second and back on (or send FR reset command) and it is back to normal for 500 - 1000 packets then the packets no longer show up again.

Thank you.