I have a very difficult problem. We have a mixed ecosystem of S2C (2.4G ZB) and SX (900M DM) nodes in our products.
We are constantly fighting some nebulous bugs whereby nodes will stop passing data packets on the network. Nodes can still be located with the ND command, but sending data to the nodes and RX data from them simply stops.
Our stack was previously working for several years, and some trivial changes (i.e. issuing DB command every 60 seconds) have recently produced this problem, only on the ZB nodes!
I can verify that reverting to our previous firmware solves the problem, but I cannot locate any changes in our latest firmware that would affect operation of the radio. The problem is quite consistent across many hardware units, however; it is most definitely a firmware problem.
I should add that we recently discovered that sending a TXRequest with an address of zero to the SX nodes causes them to exhibit a very similar problem (won’t send data), but only in one direction!