Bug Report
So this is a bug on the musescore.com site.
When you are listening to any sheet, usually there will be a "banner" looking kind of thing that appears at the end to ask you to rate the piece. And after choosing any star, that will count to the piece's rating, even yours. And normally, you can't rate your own piece(for obvious reasons).
If you are a dev and you read this, please do something with it.
Comments
This here though is musescore.org.
You'd need to report this over there on musescore.com