When I load up scores (even those saved within musescore 4) the audio is crackling and filled with little clicks like a scratched CD. This may have something to do with the fact the scores are transfers from MS2...
However, since the effect reduces with time (i.e. the longer the score remains open in MS4) I have my doubts.
Try some off the suggestions here https://musescore.org/en/node/339915
opened my orchestral score and I hear crackling in the first few bars but it seems to get better as it plays. I increased to 4024 and am playing on a Surface. What kind of system configuration are you playing this on? Power? Brand? Do I need a desktop?