When I plugged in my device for the first time it said 100% but whenever I unplugged it immediately died and won't turn back on until I plug it back in.
When I plugged in my device for the first time it said 100% but whenever I unplugged it immediately died and won't turn back on until I plug it back in.
These symptoms are typical of an end-of-life Li-On battery. The vivoactive 3, with a release date of August 2017, this is entirely possible.
Life Expectancy for the Rechargeable Battery in My Garmin Device
You can also try contacting Garmin Support.