I created a world in 1.14.4, got a shield, combined it with an ominous banner and applied some enchantments to it, but after switching to 1.15, the enchantments appear to be part of shield/banner design (they show at the very bottom in the same colour and area and everything as the design), and therefore it does not have the visual effect of an enchanted item (the animated glint). Weirdly enough, the enchantments still work.