Is Cortana sleeping?

[LightenSkies]

Hey everyone this been bugging me I notice quite a few times when I say hey Cortana on my Lumia 950 countless times she won't respond unless I once in a while just open the app then close it. Not sure if this is a bug or maybe firmware? I try this many times in a quiet setting. And it's puzzling me. Any one having this issue?

 

[mikepalma]

Return it for an exchange

 

[LightenSkies]

Return it for an exchange

Well that not helpful by any means. Clearly the phone works when it comes to using every other function. I simply want a better insight of what could be the cause it like perhaps signal or so on.