Thanks for searching for the answer you need here.
We hope you don’t mind us replying now as we just stumbled upon this thread. It might be the case that you're logged in to different accounts across your devices and that's why you're seeing irregularities with your music collection. We'd recommend that you try logging out and back in. Even if that's not the case, this is still a useful thing to do in such situations as it prompts a resynch of your account with our servers.
It's also a good idea to follow the steps in this Support page on how to secure your account. As an additional security measure, you can also follow the instructions here and remove the access to your account of any third party apps you don't recognize.
Hope this helps. Keep us posted on how it goes.
Help others find this answer and click "Accept as Solution".
If you appreciate an answer, maybe give it a Like.