Heart-rate signal missing
Versa 2 continuously tracks your heart rate while you’re exercising and throughout
the day. If the heart-rate sensor on your watch has difficulty detecting a signal,
dashed lines appear.
If your device doesn’t detect a heart-rate signal, first make sure heart-rate tracking
is turned on in the Settings app on your device. Next, make sure you’re wearing
your watch correctly, either by moving it higher or lower on your wrist or by tightening or loosening the wristband. Versa 2 should be in contact with your skin.
After holding your arm still and straight for a short time, you should see your heart
rate again.
For more information, see help.fitbit.com.
Read more: https://manuals.plus/fitbit/fitbit-versa-2-user-manual#ixzz7acn3IdHp