Touch screen active whilst on calls

[Loopy88]

Since updating to the latest android version, 5.0.2, my Z1 screen remains active whilst the phone is against my ear. For example, it will place the call I am on on hold and make another call to someone in my recent call list. It will also disconnect calls. This happens every single time. It has made the phone unusable for both making and receiving calls.
Please advise how this can be fixed.
Many thanks.

[Uliwooly]

@Loopy88

Does your phone has a protective case or film that might be on or near the proximity sensor? Does it work fine on safe mode? 

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008

[snowdrop]

Hiya.  I have found unless I press the button on the side to lock the screen whilst on a call, my ear ends up pressing loads of buttons or cutting the caller off.  A **bleep** nuisance, but I think design flaw.

[jis87]

My significant other has exactly the same problem. It's as annoying as rap music. There isn't any fix for this.