There where a few other posts talking about the sensor stopping to work. My scenario is slightly different. The device registers with SmartThings just fine, I am using the custom handler by Scott Lemon (adding minimum duration). I also tried using the native Motion Sensor handler both seem to have little to do with the issue (although, what do I know :-).
When the device is reset (remove batteries etc.) I get the two blinks after inserting the battery and releasing the tamper switch quickly. The system then goes into walk mode, during which I can see that the red indicator on the sensor is detecting when I move. I let the system sit for the prescribed 80 seconds after which I get a series of quick blinks. So far, all as expected. I engage the lock (or not, no difference), and now expect to see motion events when I move. However, nothing happens, no blinking indicator on the sensor, no zigbee events. The trigger never happens, I waited for 3+ minutes to make sure it’s not the forced delay.
What am I missing?! I have two units, both misbehaving the same way. I have a fair amount of Zigbee devices on my network (~ 15, which should be below the 32 mx limit, plus I do have repeaters in the system). I am doing the testing right next to my SmartThings hub, so no distance issue. Batteries are fresh and tested.
Does anyone here have any idea? I am about ready to throw them away and declare defeat.