ipad air 2 screenshot problem

Hello,

Would you please help me to figure out the screenshot problem about my ipad air 2. I've almost tried anything found on the internet to fix screenshot problem of the device, however none of it works.

I've tried to push lock and home botton at the same time about 2 seconds. (nothing happens)

I've turned off the device and tried again.

I' reset the device and tried again.

Is there something wrong on the device or should I rearrange some kind of settings on device ?

Thanks in advance.