Location: western Massachusetts.
A few candidates I can find: Hoogendorn holly; Rhododendron ferrugineum L.; Nerium oleander
It appeared pretty healthy last year and based on image search, it looks like Hoogendorn holly.
This May it flowers.
But unfortunately, this year the leaves are much more scarce and some of them are brown colored. Is this some kind of disease or snow damage? We have plenty of rain this Spring.