My audio doesn't copy but my video does more detail in content

I am trying to sync my audio and my video, and I have added beat makers. However, I edited the video and the audio (quite a lot) before I did this, and now the video is not synced, and when I tried to copy my video and leave the audio it lost the audio (I got the audio back with CMD + Z). Does anyone know how I could sync the audio from this stage?

Thanks