In 19w39a, the enchantment glint texture was changed. That change has not reached the programmer art resource pack yet, causing enchanted items to render incorrectly.
Enchanted items have a strange glow texture when using programmer art
Enchant glint is white instead of purple, chests have weird textures and are sometimes transparent when playing without 1.14 "Default" Textures
Resource pack version has not been increased, despite resource packs from 1.15 snapshots being incompatible with 1.14 resource packs
Programmer art chest textures have not been updated to the new resource pack format
Programmer art banner pattern textures have not been updated to the new resource pack format