When collecting Dragon's Breath in glass bottles, often the player is unable to. It will show the animation of collecting it, play the sound, and you can even see it increment your inventory slot if it's in your hotbar, but it then immediately decrements as if you never collected it. I experienced this a few times while trying to collect. Once, I couldn't collect any. Another time, I had collected 4, but couldn't collect the 5th one.