Copperbark maple looks sick
Paperbark maples are not the easiest maples to grow in our experience. However, the problem with yours is probably due to being confined in the container. These maples naturally grow 20-30 feet tall, much too big for that container. Keep in mind that the roots of trees normally extend out 1 1/2 times the height of the tree, with the majority of those roots within the dripline (extent of the canopy.) Your tree is not happy in its pot.