Be sure you have a current version of MsueScore (eg, 2.3.2) and that you created the score in this version. Also that you are not using a template or soundfont designed for use in an older version. You should find if you are using the default instruments and the default soundfonts, all works perfectly.
Comments
Sample score? Are you using MDL?
Be sure you have a current version of MsueScore (eg, 2.3.2) and that you created the score in this version. Also that you are not using a template or soundfont designed for use in an older version. You should find if you are using the default instruments and the default soundfonts, all works perfectly.