It's unclear what the instrument is in the Musescore 4 mixer
In the M3 mixer, you can assign a name to a sound patch. In this case, the Flute Espr. is called "Soprano Solo". In the M4 mixer, you can see the name assignment but the sound patch is not there. All you know is that the default MS Basic soundfont is being used. Is this a mistake, or by design?