Well, I don’t know if you are using molds or what domes she has you in. Tinny is a common complaint for new users who haven’t heard the high and the brain rebels. That usually clears up in 6 weeks or so. That doesn’t say the prescription is right on. Your audi should have done a REM test where she places tube in the ear and listens to what is the result of her settings. I didn’t know of any aids that had an unusable button although they often aren’t active at the start. The user can then select the features he wants.
Music is a nasty subject with digital aids. It is difficult to get things just right. If you do a search on Musician72, you should locate a number of threads that include engineers and other musicians. He did very through testing of brands to come up with what he felt best for him. Some professional musicians have two sets of aids. They preform with old analog aids which lack the features that can be difficult for many audiologist to adjust away in digital aids.
You really need to use the aids for a month or two to get your brain to accept the new sounds. But that is assuming that the audiologist is a very good fitter and that isn’t always the case.