Dual xdma6630
I have this same problem. It happens to me once a month. If you take the faceplace off, there is a reset button under it. Use a pen or paperclip and press the reset button. You will lose your radio presets and audio settings (bass, treble, loud, etc.), but the bluetooth devices remain.
I have two of these stereos. One in my truck and one in my car. I have never had an issue with the one in my car, so I am thinking there is a defect with the one in my truck. I'm just too lazy to dig out the receipt and take it back to exchange it.
Good luck!
Mike