Mine are made from what I believe is medical grade silicone and it is not very soft. You have to squeeze it pretty hard to bend it. I was worried it might be so soft it would be hard to put in my ear. Not the case at all.
Maybe it’s just differences in tissue structure/relative composition/amount then between different folks that cause sound differences in mold usage? Hope that either with a better fit/better venting that annoying sound perceptions go away or you habituate and just learn to consciously ignore any sounds that seem distracting right now. I do think that even in eating during a dinnertime conversation that we learn, HA user or not, that if we want to follow the conversation, not to start crunching on celery, for example, during something important for which we don’t want to miss a word said.