Edited: Nevermind, I figured out it was a glitch in the audio file. I would have deleted this but can’t figure out how to do it!
I’m not sure that this is an issue of fcp or some kind of lag in my video but I had a video and audio that wouldn’t sync properly so I decided to manually do it in the timeline. I matched them perfectly at the start of the clip and then at about 40 seconds in, the video starts falling behind the audio. Any ideas of what could have happened and if there is a fix for this?