Proximity Sensor S5


Android Question

I have a brand new Galaxy S5. I was previously running a Note 3 and had no issues with the screen locking during a call and then unlocking when I took the phone away from my ear. The Note 3 even has its own check box where you can disable this feature. The S5 is currently giving me grief as it's not locking when I take a call. Subsequently my cheeks put people on hold, mute the call and try to make other calls. How do I calibrate the proximity sensor and should I be having this problem with it? My previous Galaxy's have had similar issues, only the Note 3 spared me.