THE PROBLEM IS THE SONG STYLE YOU HAVE SELECTED NOT THE RD STYLES.
YOU USE "_SET4TH.STY" - CHANGE THIS TO ANYTHING ELSE AND REPEAT THE TRAILS. I AM BETTING THAT WILL WORK.
AM I WRONG?
There is a bug in that style.
It calls a Cajon Drum [multi] for DR of which there is no clear core drum.
Playing with the style reveals a CajonFolk16th Drum (it supposed to change minor style in a vs b part, also (No stems)
Replacing it with a stem-based drums will produce no stems.
Probably a bug with Multi drums being replaced in a style.