My garmin fenix 5 plus goes dead at random times. Sometimes when I'm sleeping, other times just after exercise, a few times during. I've always got full battery and it never switches back on immediately. It's becoming unusable. Garmin have offered a refurbished unit at a price but it feels like poor value for the money I paid. I saw many others have the same issue and recently Chris from Garmin said there was some troubleshooting to go through. Has anyone successfully sorted this issue?