Lag in Muse Sound font playback
This happened with Musescore 4.0, on Windows 10, build 22H2.
This is especially noticeable in the grand piano sound font. Starting from any note on the score, when the playback started, the first note was invariably missed ... the panning bar moved like normal, just without sound. It sounded like normal only after a second or two.
If I used the basic MS sound font, this did not happen.
AFAIK there is nothing that can be done about it.