Sound problem

I have edited this video for 2 days now, and all of a sudden, my music track just decided to "go out of sync" Instead of starting where it did before, it started the music from the beginning, almost like it had reset the music (my markers on the soundtrack is also gone)

It doesn't help to make the media offline and relink it again... What can I do?

(idk if it´s inportant, but it´s a team projekt)