3rd Volta Skipped after D.S. Jump

All the jumps seem to work as expected, except that after following the D.S. jump back to the Segno, the Player skips the 3rd Volta at measure 5, and instead jumps to the 4th Volta at measure 7 as it plays through to the end.
What is preventing the Player from observing the 3rd Volta at Measure 5 and only playing the 4th Volta at Measure 7 to the end?