Dynamics not fading properly upon repeat

1) Insert a different dynamic marking at the start and end of your piece
2) Repeat from once the dynamic is changed
3) Hear the bug

This seems to occur regardless of which soundfont is in effect. I tried changing the placement of the dynamic marking as well as including a pick up measure but it did not seem to affect the bug. I have noticed, as well, that in larger works the dynamic jumps back and forth once a repeat has been made, however, I have not been able to reproduce this.