Enchantment options disappear after enchanting Iron Shovel

I tried to enchant two iron shovels with an enchantment table with no bookshelves around it and 6 lapis lazuli. I dropped in the first iron shovel and enchanted it with Efficiency I, but when I dropped in the first one the third option was blank, I tried dropping in other items that could be enchanting but in all of them was the same. I re-created it several times on creative worlds.

Steps to Reproduce:
1. Make a new world.
2. Get and place an enchantment table.
3. Enchant an Iron Shovel.