If your watch will not pair to a phone, or if it randomly disconnects, restart your watch. You should also make sure the Galaxy wearable app is up to date, but it may be necessary to reset the app and unpair your watch. Give this link a try: https://www.samsung.com/us/support/troubleshooting/TSG01003238/
If you have tried the troubleshooting step above and are still experiencing these symptoms, I would recommend a service repair. Can you please provide me with your full model number and serial number/IMEI in a private message: http://bit.ly/2JH2rq2
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