Violin Issue

In a large score (15 mins currently) I am working on, the violin sound is very delayed and either sounds terrible or is inaudible in 16th note runs. It is, however, perfectly fine in another test score I made using only violin. Is this an issue with the score being too big? It sounds exactly the same when I upload it to the website, in case that matters. I would really appreciate help if this can be fixed; it really sounds quite awful and ruins the entire piece.