I bought a Vivoactive 4 second hand and it has caused me nothing but trouble. It randomly shuts down, even when 100% charged. I took a video and provided it to Garmin support and they offered me another Vivoactive 4 for market price. They know it is a problem and I have shown them the video evidence, but they don’t want to fix the problem as it is an old watch and they obviously want people to upgrade. All I ask for is to be able to revert the watch to a previous update so that it will work again. There was obviously a fault on the last update that they will not acknowledge.