The synchronization often stops during my sessions!
Don't worry. It may happen that the sensor disconnects and reconnects during the training session. The reason for this is an interruption of the Bluetooth connection. The sensor has to reconnect again to continue showing the data.
The Bluetooth connection can be disturbed because of the horse's body fluids which interfere with the signal. The more massive your horse, the more the Bluetooth connection may fluctuate.
This is no problem as we have thought about this when constructing the Motion. The missing connection does not influence the recording. Once the session started, the sensor works completely autonomously and records all your training data even without a Bluetooth connection. The only thing you have to pay attention to is to reconnect the sensor to your mobile device before stopping the session. This also means that you can leave your phone at the stable or elsewhere once you have started the session.