LP-CC2652RB: DEVICE JOINED, NOT ANSWERING PING PACKETS.

It’s some months we’re working quite fine on a ZigBee project  developed on CCS  studio, “zr_genericapp_CC1352P_2_LAUNCHXL_tirtos_ticlang”  (thanks a lot to Mr. Ryan who supported us each time we were on troubles…)

 Each one of our router/end devices is configured with 8+1 endpoints and we handle all our devices (at the moment) with Zigbee2Mqtt application….

 At main task application “zcl_genericapp.c” file, we continuously check the “bdbAttributes.bdbCommissioningStatus” to be   “BDB_COMMISSIONING_SUCCESS”  or “BDB_COMMISSIONING_NETWORK_RESTORED”, to see wether the device is joined on the network or not...

I hoped this was enough to be sure the device was joined to network;  but after some days of continuous testing (4 routers+16 end devices),  this morning I found a device not responding to network commands:

At Zigbee2Mqtt level I see it as the message “… failed to ping …device” repeatedly appearing!  Even switching ON/OFF attributes of each end device, nothing happens.

Please consider that an associated LED on our target is blinking in such a way, telling me that “bdbAttributes.bdbCommissioningStatus” matches the above two values. So I really don’t know what other check I have to do to be sure the device is capable to handle endpoints R/W attributes!

Here is the question: could be enough checking  the periodic incoming PING packet from coordinator? (without the needs of adding application level commands….sent from coordinator )

If so, what function call or variable check can I do for this purpose?

Thanks a lot

Roberto