They get leaf spot like photinias. I don't know if that is what you have. It looks like sunburn.

I had Clara too, and mine used to do that on the west side of my house. It is sunburn. You could put a light shade cloth over them in this heat and be sure you water diligently through the rest of summer, but to be honest, even after mine were well established, they still got some sunburn in July/August, especially if they got reflected heat from brick siding. And they do get the fungal leaf spot photinias get. When you water, be sure the leaves aren't wet when the sun hits them (water the roots). If you have room you could plant a small, open tree to provide some relief from the full West sun on the area.

I had 3 Claras I planted in part day shade a couple of houses ago. No problems at all. I agree they may not be liking the full sun.

Would it be possible to move them to a slightly shadier part of the yard and plant something that can handle full sun in their place?