Strange Clapping Noise when using Synth Bass

In the musescore program (using the default soundfont), Synth Bass 1 works just fine, with no problems.
However, when I upload any score using Synth Bass 1 as an instrument, there is a strange clapping noise that seems to go off randomly during playback. It's pretty noticeable. I know it's the Synth Bass because I've uploaded many scores, and the only ones with this clapping noise have Synth Bass 1 in common.

I don't know if this is a bug, or a problem on my end, but I thought I might report it.

UPDATE: One of the scores I uploaded about half a year ago uses Synth Bass 1 and has no problem with the noise, but scores I upload now do have this problem.