Does your "Hey Cortana" keep switching itself off?

[how1ard]

So since updating to Denim on my 930 (UK unlocked) all features are available and working. The one issue I have is that "Hey Cortana" keeps switching itself off. It is set to run in background tasks (including whilst battery saver is active) but barely stays on. Every time I switch the phone on I have to activate it? Am I being super stupid? Have I missed something somewhere? Or are you having the same problem?

 

[pmhgeneral]

"Double post" mods delete.