Hi - These are classic symptoms of Volutella blight, a fungal disease that is fairly common in Pachysandra plantings. See our web page below for photos and more information on managing this disease. If you just have small areas of affected plants, trim out the symptomatic leaves (discard them in the trash, not compost) and avoid overhead watering to minimize leaf wetness.
If you have large infected areas, you can mow at the highest setting. Thin out and rake out affected plants and debris. Taking these measures may help to the point that you don't need to use a fungicide. Fungicides protect healthy new foliage only. They will not cure infected leaves.
Here is more information: https://extension.umd.edu/hgic/topics/volutella-dieback-pachysandra-groundcover