I made some item with a special tag so the renamed item isn't in italics in MCEdit back in 1.7. before the 1.14 snapshots the items were fine with no nbt errors. But I noticed in the most recent snapshot (18w50a as of this post) they had extra nbt tags that somehow got converted into the actual item name instead of being in the nbt tags. I'm not a nbt or tech pro so i guess somethings but you get the jist of it.