Well - I thought I'd solved this by doing 3 things but no luck. I have tried the following for the 2 IRIS motion sensors (v3):
Changed driver to "device" and deleted any scheduled jobs
Changed driver to Generic Zigbee motion (instead of the one with motion/temp/humidity)
Download backup, do a soft reset and restore from backup
@jtp10181 - I have not tried your hack because the timing of the warnings is so unpredictable (it stopped for > 12 hours and then happened within 3 hours again) and while I think that it is related to the IRIS motion sensors, I cannot be sure (I have quite a few zigbee devices, so it would be quite a painful process).
Does anyone know if zigbee devices can try and update on their own (not user initiated)? Do IKEA and Xiaomi devices do something? Anything else that I should/could try?
Yesterday morning, I removed the 2 IRIS Motion Sensors (v3) from HE and I am no longer seeing the "warning" for failed firmware update (it has been over 24 hours).
I do have a need to use these sensors, so if anyone is using them on a C-5,(latest firmware) can you let me know if you are not seeing these log messages? Also, which driver are you using? Since I removed both at the same time, I don't know if I just have a sensor that is acting up or if there is something else going on.