Oh Heidi, how frustrating, and how very odd….
I don’t have the digital pattern but have just got my paper pattern out to check:
the length of the inseam on the pattern piece from the crotch edge to the hem edge is 18cm / 7&1/8″ on both the front and back shorts and this is true for all sizes.
So, it’s not the case that you’ve accidentally traced the wrong size. Since you’re out by exactly 1″ I suspect you must have overlapped the grid lines by one extra when assembling the pattern?
Something looks very wrong about your back pattern piece, the one on the top. The distance from the crotch edge to the lengthen/shorten line should be similar to the same distance on the front pattern piece – about 1&3/8″
And what’s happened to the notch that should be marked on the back pattern piece inseam? It should be the same distance up the inseam from the hem edge as it is on the front pattern piece.
I think the problem must be in the assembly of this back pattern piece.
Measure your pattern piece and fabric. It should be 18cm / 7&1/8″
I suspect your front shorts is correct but the back is 1″ too short. You can still make it work, you’ll just have to trim 1″ off the hem edge of the front shorts – it’s ok the pattern is kind of square and will allow that, but you’ll end up with shorts that are 1″ shorter than the intended length.
Good luck,
Shelley