*** (6/18/2024) Update from Allie, the pattern designer, regarding the issue with the waistband:
[I've opened the pattern files and have walked the seams and do see that the waistband is the correct length for the yokes, but sometimes the tops of the yoke pattern pieces can stretch out during sewing and ironing, so this might be part of the problem.
The main issue, I think, is the seam allowance adjustment. Since you adjusted your side seam SA's to 3/8", you'll need to add 1" to the waistband length (since each side seam essentially has 1/2" more fabric (1/4" multiplied by 2 for each seam). I would cut a new waistband, adding at least that much additional length, but would recommend adding ...