I went for a run with the MI Band 3 and after I came back I opened it and kept it on the table. After a while I saw that the heart rate senson is still on. I tried to take the heart beat without putting it on the wrist and it read some bogus numbers like 120BPM or 150BPM. I unpaired it and the senson turned off. After I again paired it, the sensor turned on after a while all by itself. I keep the automatic heart beat sensor off but it still turns on by itself. The sensor remains off if I keep it unpaired. Its a software bug. Please fix it.