The sound button of U11+ doesnt work !!

[Android Central Question]

I just get my U11+ a week ago, it work pretty fine (sound button) in first couple minutes, then there is no response when i pressed the sound button (both up and down). however, i can still capture the picture by pressing both Downward key and power key. can anyone solve this problem please

 

[Rukbat]

It's under warranty - bring it back.