That's holly leaf spot. Both Carolinas are fertile breeding ground for it and that's about the time of the year when it starts to make itself felt.
You may see different symptoms because holly leaf spot is caused by a complex of several fungi but rest assured: it's that disease and unfortunately several of those fungi can attack other plants, just like you are seeing.
What to do know? Most websites will give you the usual recommendations to prune, clean etc. All is good and well but pruning and raking won't cure already diseased plants.
You should treat the plants with a fungicide, if not now at least in the spring to protect the newly formed buds during the most vulnerable phase.
Copper-based fungicides work reasonably well against all kinds of leaf spots, are cheap, easy to store indefinetely etc but need to be reapplied frequently to be effective.
Wide spectrum systemic fungicides such as triazole- and myclobutanil-based ones are extremely effective against leaf spot and require few applications (often just once or twice a year) but since they are often sold in large formats (1/4 gallon canisters being common) they are pricey, need to be stored properly and often have an expiration date to boot.
Your call.
