Rotel A 12 and Chromecast Audio

Hello,

I have connected Chromecast Audio via optical cable to my new Rotel A12 integrated amplifier. I am using HiFi cast app on my android device to cast music from my local folder. I can't get to have CCA play 24/192 at all. It plays only 48 or 98khz. Am I missing anything? Is it a problem with CCA or Rotel or something else? The customer service support teams just blamed one another.

Appreciate some feedback. 

Also, if you're aware of this amp, can you confirm if the USB (front) port is only for Apple devices? It didn't recognize any of my USB devices. 

Thanks for your time!

Best,
Krish