I had the same issue. Try this, search for new lights and then push the button of the sensor.
Don’t reset the sensor (long press)!
This worked for me several times with various xiaomi sensors!
Also have a look at your firmware version:
I had the same issue. Try this, search for new lights and then push the button of the sensor.
Don’t reset the sensor (long press)!
This worked for me several times with various xiaomi sensors!
Also have a look at your firmware version: