Micro:bit connected but can't read megneto bearing

Trying to connect micro:bit with smartphone by app inventor app.

download the sample .aia file form the follow webpage and try it:
http://iot.appinventor.mit.edu/#/microbit/microbitbutton

the head of the bee is keep continue changing very fast as well as the
data X, Y and Z keep changing event it put it on table steadily.

anything wrong ? what is the sample makecode i should uploaded to micro:bit ?

thanks a lot

p.s.: the text for label3 is keep on the screen as well as screen 1 at the top, it seen bearing and period is not in function