I picked up the school's soprano a few days ago and have found it impossible to play the palm keys. It's a well-regulated Yamaha YSS-62 so the horn isn't the issue. When I play alto it is impossible for me to play the palm keys without biting and suffering the pain later on. On an alto mouthpiece the highest pitch I can get without biting is around a concert E. I'm aware that's an issue and I've been working on it for around three years now with absolutely no success. Using a Yamaha 4C with Vandoren 3s gets me an A on the soprano mouthpiece, but biting no longer is working as a quick fix for my upper register. I highly doubt my embouchure is an issue. When I play high notes I put my tongue in a "hee" position and think of blowing through the mouthpiece with a supported airstream. Any advice on what else I could do?