Nokia Lumia 930 - product

U.K. carrier O2 has rolled out the Lumia Denim update for Microsoft's Lumia 930, but it comes without always-on Cortana listening. The company says it is investigating the problem, but it's unclear for now why the feature isn't present.

Lumia Denim brings all kinds of improvements and new features to Microsoft's own Windows Phone handsets, including support for 4K video recording and Rich Capture, and other useful camera improvements. Its headline feature, however, is Cortana listening.

This enables Cortana to listen for "Hey Cortana" commands at all times while the device is switched on — even if it's in standby mode — so that users don't have to activate the digital assistant manually. It's just like the "Ok Google" feature in Android. But for O2 users, it's nowhere to be seen.

Many have taken to O2's forum to complain about the issue, and at this point, its omission remains a mystery. However, Chris from O2's social team has confirmed that the carrier is looking into it.

"I understand many of you are unhappy around an issue with Cortana functionality being missing," he said, "please leave this with me and the device team, we'll find out what the issue is and report back."

For now, then, Lumia 930 users on O2 will have to wait a little while longer for this feature. Hopefully Microsoft and O2 will be able to fix it with a simple patch, but until we hear more, it's hard to tell how long that will take.