Blackout issue in Vivoactive 4

Hello, a few days ago I plugged my Vivoactive 4 into the charger, disconnected it at 100%, and the screen blacked out. Upon plugging it back in it restarted but went black after being unplugged. It will fully function on the charge but when I plugged out of the charger it is black out. My Vivoactive is quite new (1,5 years old). Any advice apart from sending it to local technical service?