Now Playing Incorrect Account

[thefourthsoul]

In the past couple days, in the Now Playing widget in my Notification Center, Spotify sometimes shows what my brother is listening to rather than what I am listening to. As a result, whenever I press the pause button on my keyboard, it pauses my brother's Spotify rather than my own. This is a huge inconvenience for both of us and I would like to know how I can fix this. I am using a Macbook Pro running macOS 10.14.4. My brother uses Premium and I use Free.