I've had that with one old Android version, but I can't remember which. Sometimes when the map auto returns to current location or I pan in certain ways. But I couldn't put my finger on it.
However, the OP sees the camera view not just the sound. My guess is that it is a hardware button or some shortcut that accidentally activates the camera. The logs would show if Waze has anything to do with it. I just hope he doesn't forget to report back here
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