Adapting might be the key. That's exactly how I started to feel too this season. Doing more tournaments, I realized even my shuttles were behaving differently in different halls. And my opponents always have different shuttles too. I decided to stop using a specific shuttle for training matches and instead bought several brands and grades (same speed though) and mixed them in a tube. I test them though and unless it's really fast or slow I just play with it and try to learn how to adapt. Because that's what I feel I have to do to progress on that aspect of the game and stop trying to control that shuttle element too tightly during tournaments. It can be quite draining mentally to always think about the shuttles and their speed instead of focusing on the actual game.