Default [Q] Xperia V Random Display Clicks

My Xperia V sometimes clicks on itself, always on the right virtual button. Switching off the screen sometimes helps, sometimes I just have to wait. Cleaning the screen isn't the solution. Also, I don't see any scratches or anything like that. This problems occurs with both firmware versions, 9.2.A.1.199 and 9.2.A.1.210.

Another problem is that switching off the Wi-Fi doesn't work. In the battery stats it's always on and it also drains a lot of battery life