There is a gap between rails and stiles on a 5 piece door

The tongue length measures at 0.5" (needs to be 0.375") . Which is causing the overall rail length to be 0.25" short

In the "S" workbook, the tongue length is set to 0.375".

If I change it to 0.5" that "fixes" the gap, but in the end i still need have the tongue length be 0.375"