After going through a list of Unique jewelry pieces and their enchantments to compile a spreadsheet, I noticed that one stood out from the others of its kind. The item "Serrin Vol's Advantage of Cyrodiil's Light", the ring acquired sometimes from defeating Serrin Vol, one of the bosses in the Pothole Caverns delve in Cyrodiil, has a Weapon Damage Enchantment which grants 9 Weapon Damage, rather than the updated Multi-Effect Enchantment that grants both weapon/spell damage and stamina recovery:
I've tested this bug and couldn't find anything serious, but this is an unintended feature that should be fixed in case the bug leads to anything bigger.
PC/NA — Lone Werewolf, the Templar Khajiit Werewolf
Werewolf Should be Allowed to Sneak
Please give us Werewolf
Skill Styles (for customizing our fur color),
Grimoires/Scribing skills (to fill in the holes in our builds), and
Companions (to transform with).