Nope, this is a different bug, but it is similar. My shield is not enchanted, only my sword and my iron boots. This isn't really a game breaking bug, it's just something I noticed when I got my enchanted diamond sword and the glint wasn't rendering on it. And there is no enchantment glint on the shield, not even on the handle. I dropped it on the ground to be sure.
And, before anyone comes back and says I'm wrong, both those bugs listed in the previous comment had to do with an enchanted shield or an enchanted chestplate. As you can see in my screenshots above, neither my shield nor my chestplate have an enchantment glint, meaning their not enchanted. Only my iron boots, crossbow, and diamond sword are enchanted. On a side note, regarding the bugs above, I have never encountered those issues, and I'm playing snapshot 20w09a. And when I say never, I mean never. Not in any of the affected versions that those particular "bugs" affect.
On last thing: if no body can confirm this, I will take it as an issue on my computer's end.
Issue is linked with shields decorated with banners that have patterns on them. Please look at attachments for my proof.