Severe Dynamics with Muse Sounds

I've found that, when working with Muse Sounds, the dynamics tend to be a bit severe, especially when dealing with softer dynamic levels. I've attached a file to show what I mean.

When I hit play from the beginning, I hear nothing at all from the trombone in the opening bar. I open the mixer, and there is nothing in the trombone channel until the second bar. This is, apparently, 'mezzo-piano'? And this isn't the only time I've encountered this issue. 'Piano' and 'mezzo-piano' are often read as 'nothing' by Muse Sounds, and this strikes me as an error to be resolved.

Two things worth mentioning: I haven't done any mixing on this file other than lowering the fader on the organ channel. Also, this is only a problem with Muse Sounds. If I change the sounds to MS Basic, the sounds themselves are less realistic, but the dynamics are much more reasonable.

I'm using MuseScore 4.2 on Mac Sonoma.