The iTunes algorithm for shuffling a playlist is total shit. I have a 10 hour “90s on 9” playlist, where I’ve heard some songs every single time I shuffle while others have never come up.
— “Bad” Billy Pratt (@KillToParty) February 12, 2020
It likely uses a naïve shuffling algorithm which tends to do things like that, instead of a Fisher-Yates algorithm. Too many shuffle functions are bad for just this reason.