" Both audios are in 44.1 Hrz. "
Not sure I understand this statement . . .
So you were shooting video of a lipsync performance to a CD? . . and you imported the CD sound into your session? . . . and it won't sync up to the performance reference audio? . . . . This sounds like the classic sample rate mismatch 44.1K CD vs 48K, standard video sample rate.
It sounds to me like you'd need to do a sample rate conversion of the CD audio.
Rick Crampton
