Many of the Charr cultural armors and a few others severely mess up location of shield on a charr character, moving it into the arm for some reason. The pieces for the glitch can be easily determined by previewing a shield in the “Wielded” form with the offending piece of armor. I spent a few minutes checking which ones did this: here’s the list of which pieces move the shield into the arm.
Headgear: Archon Helm, Fanged Dread Mask, Flame Legion Mask, Harelequin’s Mask, Heritage Masque, Invoker’s Helm, Mind of Koda, Phantasm’s Mask, Priory’s Historical Cowl
Shoulder: Archon Shoulders, Flame Legion Epaulets, Heritage Mantle, Invoker’s Shoulders, Mantle of Koda, Priory’s Historical Mantle
Chest: Archon Coat, Flame Legion Vestments, Heritage Greatcoat, Invoker’s Coat, Priory’s Historical Vestments, Soul of Koda
Gloves: Arms of Koda, Flame Legion Wraps, Heritage Gloves, Invoker’s Gloves, Priory’s Historical Gloves
Leggings: Archon Leggings, Heritage Pants, Invoker’s Leggings, Priory’s Historical Pants, Way of Koda
Boots: Archon Boots, Flame Legion Shoes, Heritage Shoes, Invoker’s Boots, Path of Koda, Priory’s Historical Shoes