Music Video - locking tracks

I am somewhat of an FCP rookie, so my question may not be phrased perfectly. I have a soundtrack with a group of musicians. I record and edit the audio in my studio and then create a wav file that I use as the audio. I then have the musicians play to their soundtrack outside using a bluetooth speaker, and I record the video with two cameras. I sync the video tracks manually to the actual soundtrack. Then of course I do not use any of the audio from the two video tracks.

With the project I am working on I did multiple edits and transitions, going from one camera and cropping sections. As I got into the song I realized the edited parts are no longer in sync with the audio track. Something has moved them on the timeline. I have gone back to the beginning of the song and undone all of my edits so now I dealing with an audio track and the two synced video tracks from the two cameras.

I don't know which transitions or effects have caused the video tracks to become out of sync. Is there a way to line the two video tracks up with the audio and then "lock" them so that when I do edits the video tracks do not come out of sync?

That seems pretty basic, but I am confused about how to do this. Any tips will be much appreciated.