Tiktok copyright

Does anybody else understand TikTok, copyright? And how it works and how to avoid it. I have such a hard time with it. I will see people using the exact same song I did, And their video stays up but mine gets muted. I see people posting full music videos. So it's just very inconsistent. It doesn't add up and ill even alter the audio and im only using a piece of the song anyway not the whole thing and it gets muted.

Plus theres no way to appeal anymore the option is not there for me.