Lumia 520 doesnt have a front camera but it has a sensor which gets enabled the moment you receive a call. But after 8.1 update using preview for developers it not working anymore. The sensor is not getting activated when i receive any call. It behaves crazy when speaking opening up what ever gets touched on the screen. Is this a copatibility issue with Lumia or did MS miss out on some thing? Is anyone else also having this kind of issue in thier Lumia 520?