Percussion Instrument Change

I am having trouble changing from Xylophone to Cymbals in a piece I am writing. I have already used the "Change Instrument" setting, but the amount of lines won't change. I have no trouble changing from unpitched percussion to unpitched percussion, only from pitched to unpitched. I have done this before the other way around (from one line to multiple lines), so I know it is possible. What am I missing?
Thanks in advance :)