Need help! Frankenmesh weight problem

The bath towel you cloned is made of 3 meshgroups, two of which are in the calf area. This is done so that the garment properly interacts with boots ( when you put on boots, the meshgroups in the calf area disappear to prevent clipping.
You imported the blend file that contains only one meshgroup and only one of them, the lowest one, was replaced.

- clone the bath towel again, export its blend, open it, delete s4studio_mesh_2;
- File - append - your nightshirt - object - s4studio_mesh_1. Select s4studio_mesh_1.001, switch to Edit mode, select faces from ankles to knees, and delete;
- change s4studio_mesh_1.001's cut number to 0002, save, import in the bath towel package you just cloned.