This appears to be two different types of fungal leaf spot, a not-common occurrence with winterberry and fortunately not of great concern in this case, as the berries seem to be unaffected. When the leaves shed late this autumn, you can rake them up and dispose of them to reduce the risk of spores overwintering and starting new infections next year. It's not a foolproof measure, because spores can also blow-in from other areas or splash around in rain, but it should help to reduce the risk of more severe disease several years in a row. Wet leaf surfaces are often easier for disease spores to infect, so if you happen to irrigate plants in a way that wets the foliage, either water early enough in the day so that foliage can dry by nightfall, or avoid wetting leaves by watering only the soil.

Although fungicide use might help to reduce infection in a future year (as it cannot cure existing disease), it would require spring application (well before symptoms manifest) and probably multiple repeat applications each year, and may have negative consequences for pollinators or other organisms, so we usually do not recommend its use. If berries become infected by a fungal "leaf spot" in a future year, though, they might abort and cause the plant aesthetic damage in the sense that it would diminish or decimate the fruit display for that fall/winter. Years with wet, cooler spring weather (as we had this year) will tend to pose a greater risk of plant disease outbreaks than years with drier spring weather.

Miri