Unable to set Dynamic Range to "Staff."

I have two issues that are very closely related. They both deal with the "Staff" option in "Dynamic Range."

First, I chose an instrument, which originally is trumpet. In the "Instruments" menu (by pressing "I"), I added a staff to avoid dealing with voice crossings and a cleaner score.
Then, I selected two different dynamics and place them on the score in different staves. On each, I clicked on the dynamic and clicked on "Staff" in the "Dynamic Range" part. The top staff should play its dynamic separate from the bottom staff, but on playback, there is often an awkward mix.

In excerpt 1, the trumpets are all playing mezzo-piano (the top is supposed to be playing fortissimo and bottom mezzo-piano). This only differs if the top comes across any articulation marking (I tested accent, staccato, marcato, and tenuto. Slurs are ok.) which gives awkward pulse/accent type sounds. I checked to see if it works on piano, which it does.

In excerpt 2, both instruments do the same thing. The bottom staff is completely ignoring the crescendos and decrescendos its given, however it is still playing the letter dynamics (p, mf, f), which is odd.