Technology is excellent, but it is not foolproof. It sure would be nice if it were, but the reality is, technology can malfunction through no fault of your own.
Sometimes, if you are trying to sync the tracker to your smartphone, you will run into issues, and it will not allow you to do so. There are a few troubleshooting steps that you can take in case this occurs. Firstly, ensure that you are both indoors and that the two devices are close to one another. The closer they are, the easier it will be to sync, and sometimes outdoor light can interfere with the process.
Also, even though it is a simple mistake, ensure that the Bluetooth on your smartphone is turned on. If you are still having issues, reset both your smartphone and fitness tracker.