Screen not turning on when receiving calls

[dil]

Whenever I receive a call, my phone vibrates two or three times, then it starts ringing, and then the screen turns on after about 2 seconds. So, I have to wait for the screen to turn on to answer the call. Anyone else experiencing this?
Any suggestions?

 

[minmongoblin]

Running a heavy app like Home++?

 

[dil]

No, I'm not using Home++ or any similar app

 

[cereal killer]

powercycle the device......