If you have armor OR elytra equiped with any enchantment, the enchantment glint will not show in your inventory preview, or in third person mode. This could be a problem when getting confused in tight situations if your armor is enchanted or not, and can be annoying in most cases.
Environment
Java Edition, 64-bit operating system, x64-based processor
Check F3 debug screen to confrim those screenshots were taken one after another, with the only thing changed is the inventory GUI