single note crescendos, decrescendos and fortepianos don't work when using soundfont addons

i am using the soundfont addons 'timbres of heaven', 'aegian symphonic orchestra' and 'concert band', and when i try to add dynamics to individual notes, the note will only play at the initial set dynamic, and its volume will not change.
i.e., if i want a whole note to increase in velocity over one measure starting at mp and ending at ff, it will stay playing at mp even though i have added crescendo hairpins and dynamics properly.
forte-piano dynamics also do not work. any help? i am using mainly the 'concert band' soundfonts for each instrument.