Siri not working on my 6+

[Vortec 5.3]

When I try to ask
Siri something, it responds by saying I didn't get that. Or I'm not sure what you said.

I've tried toggling on and off Siri. I tried hitting the home and sleep buttons to reset. I tried resetting network settings and toggled on and off dictation. All to no avail.

Any clues why Siri isn't working? My iPad works perfectly. And I have the latest software update on my phone and iPad.