Hello!

How old is the SD card in question that you're using? If you instead do not put the song on the SD card but save simply to the desktop or another folder on the computer's internal harddrive a couple times as a test (perhaps in a music folder on the C drive?), does the sound issue continue? If it does, then it's worth digging into your audio settings more in depth.

It's worth noting that SD cards have limited read-write cycles. In short, the SD card is always degrading gradually. Thus, its lifespan is finite and as it reaches the end of its cycle it can start to cause strange behaviours, increase the chance of file corruption (although typically this results in the files not being able to open), etc. So if we cut out the SD card, just as a test, I am wondering if the behaviour continues.

Cheers,
Ember