I thought I read on this before but I can't find it. I typically take a route in RideWithGPS, and using Connect IQ will load it directly on my Garmin 830.
On some routes, I seem to get cues just fine over by BT headset. On other routes, I get a turn notification on the device, but no audio cues. The routes look similar on RideWithGPS; nothing obvious jumps out to me. This may be a Garmin thing, a RideWithGPS thing, or a setting somewhere. Any suggestions on what to check?