The audio isn't perfectly aligned with the video. I'd recommend restarting the animation a few times. I've also heard that giving the project a like could help. ;)
Yeah, I've been gone for a long time. I transitioned from Scratch to learning an actual programing language. >:D Nowadays I mostly work with GameMaker Studio but my mother is also teaching me Java. Additionally, I've got better software for animation but I realize now that more expensive/expansive does not equal better results. Sometimes a pen and paper (or maybe a 3DS) is all you need!