I have called AstraZeneca 5 times, have 5 different case numbers with them, they have ordered 5 replacements for me, but don't work any better. I have seen no evidence that anything is done to improve the units. So, I went back to Trelegy which I was using before. With doctor's help of course. Unless I hear of a "fix" for these inhalers, I will stick with the Trelegy.