You can jump and press space to glide all you want if you are sprinting and you'll hear the sound, but you won't actually start gliding often.
It will work for a while but then suddenly there will be a long streak of it not working. when it stops, you can let go of the sprint key and it works again and will continue working for a while.
Yes, I always have plenty of stamina when this is happening.
Also, when it comes to Charm of the Raven, if there is so much as a pebble or the tiniest of inclines, it won't take off. It's a little frustrating.
