Have you got all your realtracks on the main drive or external ?
Your Hold/Shots should be in Band-in-a-Box/RealTracks/LibraryM/Holds and DI in Band-in-a-Box/RealTracks/Direct InputLibraryM/Holds

So you have C... will hold and ring that chord until another chord is entered.

If you drag one of the m4a files into a DAW or Garage Band you will see there's a hold that rings out then 4 shots for that chord then the same for the next chord . .

Go to the RealTrack picker and look for the Holds column, this will tell you what hold is being used in the LibraryM Holds folder
To change what hold is used for the RealTrack > Soloist Editor > choose RT > More. set the hold number.

In Additional Song Settings:
Allow RealTracks Shots, Holds, and Pushes
When set, this song will support Shots, Holds, and Pushes for those RealTracks that have them (as shown in the “H”
column of the RealTracks Picker).