Pachysandra browning

In early winter, our pachysandra bed start to brown, especially close to the road, but not exclusively. This bed is at least 5 years old and usually does fine but not this year. An article in the Sunpapers suggested a fungus might be the cause and to cut it down. Attached is a photo of a relatively healthy looking specimen while other areas are almost all brown. I am sending this photo to ask if you see any other issues and what we should do. Are there any treatments you would recommend? Thank you.