It could be one of the following reasons:
- Make sure you have been through the Activity onboarding and set up your tracking.
- Make sure your device's battery is not dead and that it is syncing to the app.
- Make sure the device is snug to your wrist.
- The device only tracks walking, running, and biking (but not stationary biking). If you hold something in the same hand as the device while walking, it might not count all steps accurately.
- The device might be in recovery mode. If so, tracking and notifications will not work. You will need to do a firmware update to get things back to normal again.
- We use sensors and a complex algorithm to determine when someone has taken a step. We believe our algorithm is an accurate representation of actual movement and ignores false movement like simply moving your arm.