Tree leaves dying?
This looks like a native flowering dogwood with a fungal disease known as powdery mildew. It's extremely common. Here's info about it: https://extension.umd.edu/hgic/topics/powdery-mildew-trees-and-shrubs
If this occurs chronically and the tree weakens, replace with a dogwood variety that is powdery mildew resistant. They are listed at the bottom of the link.