Choir desynchronization

I saw this problem brought up in another post but there was one answer that simply took it and said "I don't have that problem, what are you talking about?", but to the point.
I'm trying to write a choral part for a project and the choir voices of the MuseSounds pluggin are desynchronizing with the tempo. It's not even an 8th note or anything like that, but simply by milliseconds and is driving me crazy. Is there any way of disabling this or do I just have to wait until they fix it?