I'm trying to hook up my iPhone XR to a Pro-Ject Head Box S2 Digital Amp/DAC. In looking at several places on the web, I determined that I first needed an Apple Camera Connector Kit adapter, which I have. I've connected it to the Lightning port on the phone. I than ran a USB-A to USB-B cable from the CCK to the input on the back of the Head Box. I plugged the Head Box into the wall, and plugged in my Grado 225e headphones. However, the Head Box does not seem to recognize that it is hooked up to my phone (the blue light on the front of the Head Box is still blinking, not solid, and no sound is coming out of my headphones.) Has anyone encountered this issue? Is there a setting I might need to change on the iPhone? (FWIW, I am trying to hook this up to get better sound from Amazon HD on my phone). Thanks.