Siri not working over LTE in iOS 8.4
I updated my 5s (AT&T) to iOS 8.4 this morning. When I tried to use Siri to voice dial (or anything else) the phone either didn't respond, responded with a list of things I can ask, or (finally), Siri saying "It seems I've lost my internet connection." But, I wasn't even trying to use the internet to make a call. Also, other internet apps work. Siri works fine over Wi-Fi, but that does not help when I'm driving.
Anyone else having this issue?
iPhone 5s, iOS 8.4