Filter Feature Problem

[Ruffles1]

Recently I was listening to my Playlist when I noticed something strange. The first song on my Playlist is called Dead Man Walking (Overture II) and on my playlist, I decided to filter the songs so I could only listen to Three Days Grace. However when I filtered, I didn't get only songs by that band. I thought it could be because I was using the shuffle play button, but when I clicked on the first filtered song, it played Dead Man Walking. The same applied with the second filtered song, except it played the second song on my playlist. I can't seem to fix it and now I can't use the filter tool the way I have been for a while now. Can someone help?