"MuseScore GM High Quality" soundfont Piano presets all Very Quiet

I will try to come back to this issue with more details later, but the short version is, as in the title, that the Piano presets in the MuseScore fonts are very quiet, but everything else seems normal.

I am running it in Unity and made a few changes, but again all the other presets sound fine, so there is something that they are doing with their piano presets which is triggering some bug in the way MeltySynth is working in Unity.

The soundfornt is an SF3 that was converted via polyphone to sf2, so it could be a Polyphone issue.

Sorry for the rushed issue, I'll be sure to come back and improve it within the week with a workaround if I find it.

Thanks for making this! It's really great!