Thanks for replying. But threshold values are not the problem. They are the same as before, and the sensor has not reported in days. (Unless I press the button, in which case it reports exactly once, then goes back to sleep forever.)
After changing batteries to all sensors, two more sensors are now showing the same weird behavior. They report data only when the button is pressed, never report otherwise.
1) What else can I try?
2) Are the H&T led blinking behaviors/meanings explained somewhere? (I mean explained properly, not the joke of a manual the device was sent with.)