YouTube uses automated systems to identify copyrighted songs, and the system typically doesn't know the difference between piracy and properly licensed music. Thankfully, disputing the claim is a simple fix most of the time.
Begin by disputing your claim with YouTube and when you get to the box that asks you to explain your claim, simply write, "Licensed through Muscle Mixes."
That should take care of it, but if you continue to have issues, please reach out and we will work with you to ensure it's resolved in a timely manner.
*Please note: Some songs cannot be monetized on YouTube
More on how to dispute a claim here: https://support.google.com/youtube/answer/2797454?hl=en