I don't know about you and your experience, but I used to have an issue with that "stuffed ears" feeling you're talking about; but I got used to it and I no longer even notice it.
It may be the same for you, if you also have the same issue with high-grade passive earmuffs. Most people who try on my 3M Peltor X5A muffs report a similar "stuffed ears" feeling.
Anyway, hope this is something you can overcome, because the far side of overcoming it for me was really great!
While I appreciate your optimistic assumption that “it’s something I can overcome” if I just grin and bear it, it’s been fifteen years and shows no sign of fading, so I’m not really holding my breath at this point. Clearly your perceptual system was able to do so using exposure therapy, but that isn’t at all universal.
It may be the same for you, if you also have the same issue with high-grade passive earmuffs. Most people who try on my 3M Peltor X5A muffs report a similar "stuffed ears" feeling.
Anyway, hope this is something you can overcome, because the far side of overcoming it for me was really great!