Certain instruments aren't affected by dynamics on playback

In the attached score, the harpsichord and viola (both Muse Sounds instruments) always stay at the same volume when played back, regardless of dynamics. The accordion (imported soundfont), hammond organ (also Muse Sounds), and drumset (MS Basic) all work fine. Does anyone have any idea what might be causing this, and how I could fix it? I'm working in Musescore version 4.0.2.230651546 on MacOS Ventura 13.3.1.