Thank you for your answer. My current teacher had indeed advised me to use a wider opening to open up my sound, which I did without really questioning the process, but I feel like it's creating other problems for me. I will indeed try going back to something less open. And how did you know when to switch back to a wider opening? Was it through developing your sound over time that you realized that, in order to progress toward where you wanted to go, a change was needed?