It may be that your sound source only sustains the piano for a few beats. Also, unfortunately, I don't believe there are defined holds for all the RealTrack instruments, so you might want to check if the piano you are using has them (you can see this in one of the columns of the RealTracks Picker, not the StylePicker).

Is this at the end of the song or the middle of the song?

If at the end of the song, BIAB has a quirk on a held chord. What you need to do is enter the held chord (using the three dots), and then where you want the hold to end, you need to enter a chord with a single dot (for a "rest"), but it can't be the same chord as the hold. I know that may screw up notation, but it is what it is. I usually just do something like:

|C... / / / | / / / / | / / / Csus.|

John

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