Playback chooses its own dynamics, ignores what is written in score.

Hi, I have piece that ignores my score dynamics and periodically (an consistently, if I play it several times) drops or raises the volume at certain points in the music. I changed, through F8, the dynamic markings (using "select all elements") from Part to Staff and even changed it back and forth between the two, in case it didn't catch it the first time, but it still has the problem. In one case, for example, I wanted the volume to rise a little but it would not, even when I changed the dynamic marking to "fff". I have included a sample where it gets loud and will not drop for the "pp".