My active 2 is flickering when it is not active. It is usable when I look at it but will go back to flickering after a few seconds.
Have you attempted to reset the watch recently?
Also, If you don't mind providing the full model code and the serial number in a private message so I can look further into the warranty status? http://bit.ly/2GGul4
I have tried to reset the watch and it is now unusable because of the screen flickering.