Why wont audacity let me sink up the same performance recorded from 2 different sources? I did it once but no luck now?

ive got one song live and i recorded it with my interface AND I recorded with a camera that has it’s own audio/microphones/storage. I have done this successfuly once before using audacity but it is not letting me get the two sinked up any closer than about a second off? After spending an hour last time and at least an hour this time I give up.