Why won't any music I download appear on Xbox Music?

[Windows Central Question]

I don't own an Xbox 360, nor an Xbox One, so I only have Xbox Music on my laptop. The problem I've been having is that since the 11th of June I haven't been able to add any music to Xbox Music. Before then, any music I downloaded would automatically appear on the app, but since then, any song I've gotten just won't show up for whatever reason. All of my music has always stayed in the same place, so I don't think the location of my music folders is the issue. I also haven't received any kind of update for Xbox Music, so the issue I've been facing seems to have just come out of nowhere. Has anyone else been facing this issue? Or better yet, is there an easy solution that I can resort to fixing the app?