Walgreens Activity Tracker

Hello 

I've just got the Striiv Fusion. When the screen is black, it says that i have to double tap the screen to see the time. 

But that doesn't work. When i want to lit the screen I have to shake very hard (which add more steps i take) with my arm. 

help? :) 

I have the exact same thing. double tap doesn't work for me and i have to shake my hand to see the screen.