Irish Flute Glissando

A hallmark sound of an Irish flute is the sweeping glissando from one note to another.

However, because the sound engine in MS4 uses the same (?) source as the normal flute (and not an Irish), I wanted to add glissandi to emulate this. Problem is that even a straight glissando sounds the individual notes on playback, like a simple run. Am I missing something?

Thanks for any advice.