iTunes keeps removing music from my playlist

My iTunes is running the latest version.

This has been happening for a years now. I have a live playlist setup for my "loved" music, when I Love a song it goes into that playlist which I play on shuffle. I've noticed many times the number of songs in the playlist goes down, when I check for a song I know 100% I have Loved, it has been unloved so it's no longer in the playlist.

Does iTunes "unlove" songs you haven't listened to in a while? It's a large playlist on shuffle so there are many songs that don't get played for quite some time.