I have the same problem and RESTART doesn't fix it.
Best AnswerSometimes, it takes several tries. If it still doesn't work, the only thing left is a Factory Reset. Go to the Settings App and scroll down to "About" and then Factory Reset. You will lose everything you have added or changed since the day you took the tracker out of the box.
If you don't want to be that drastic, you could try Customer Support first.
Best AnswerI've read where restarting both gets things back on track. Also, if you have a Windows 10 computer with bluetooth 4.0, you could download the App and update from there.
Best Answer