So my sister used to casually take classic lessons while in high school. A couple years ago she decided she wasn't interested anymore, so we had this digital piano gathering dust.
Been waiting to learn a few chops myself. So I decided to power it on.
And this was the issue I came across. In at least two keys.
It doesn't matter how soft I play the note always comes as if I slammed the key with a sledgehammer. Sometimes it even comes out as a kind of 2 note trill rather than one note.