Why is the data transfer not working (anymore)?

For a functioning data transmission, it is important that the sensor is correctly attached to the body with the belt. Make sure that the right side of the sensor is on the side of the body. On the back of the sensor are at the contact points in each case an R and an L against.

Make sure the R is on the right side of the body and the L on the left side of the body.

If data transmission suddenly stops working correctly or stops working, remove the sensor from the belt, turn it, and re-attach it. Or you simply turn the entire belt so that R and L are in place.
Now try again during training to allow data transfer.