I have a 2018 T/A 392 with the Alpine 9-speaker 506 watt factory system. Sometimes no music comes out of any speaker. Once in a while, no music, except you can hear the beeps of changing functions on the radio, so there is sound. Mute/unmute, volume up/down, etc changes nothing. AM, FM, XM, Bluetooth music, Bluetooth phone all look like they are functioning fine. Power on/off, turn off car, back on... once in a while fixes it. But lately, parking it for an hour and then there is music again. Thoughts?