DDJ-SX2 problem Effect 1 -section buttons?

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The buttons don't respond when pressing "on" .

In the software I can set the FX "on" and then the effects are working and also on my DDJ-SX2 the lights get blinking. 

But I cannot set them on and of from the hardware. 

With the FX2-section there is no problem and it works as it should. 

I Have the controller bought today so I am confused if there is a hardware problem or I am doing something wrong?

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