Here are two screen prints of my notes, one of L3 and one of L4:
L3:

L4:

Note in L3, all of the note icons are grouped by the same color. This is because they are from the same note file. Now take a look at L4, there is no sequence in how the colors are grouped together.
In the L3 screen print, my notes are in this sequence: Lectionary Year C, Lectionary Year A, Note file 1 for year b, Lectionary Year B, Hymnal (others), Hymnal (With One Voice ~ WOV), Note file 2 for year A, Note file 2 for year B, Class notes from seminary, Hymnal (Lutheran Book of Worship ~ LBW), Note file 1 for year A, Hymnal (Evangelical Lutheran Worship ~ ELW), and Hymnal (Worship and Praise ~ W&P).
In the L4 screen print, my first several notes are in this sequence: ELW, Others, WOV, ELW, Lectionary Year C, ELW, note file 1 for year A, note file 2 for year B, note file 1 for year A, Lectionary Year A, Lectionary Year B, LBW, W&P, WOV, LBW.
All of the notes within the same note file should be grouped together,