If the Sop. and Alto "move" together, create 2-note chords. Do the same for T and B. The software hasn't been able to hold one note while another moves. (e.g., an "Amen" where S holds the Ah for a half note, while A sings two quarter notes). The work-around is to show it all in quarter notes and tie the Sop line.
The other option is do Alt + P to bring up parts. add two more lines, one for A and another for A. Even if they show up in the wrong place,, you can highlight each one, and move it up to the right level in the stave.