For some reason when i receive a phone call the call shows up for a second on my Nex screen and then the system just shuts off. I'm usually connected on Digital adapter mode with bluetooth on my iPhone 5s running Appradio. When my screen shuts off I'm forced to answer the call using my steering wheel and my phone shows me who is calling like it normally does. Any ideas why this is happening? I would rather just answer calls using the Nex screen like I'm suppose to.