The Gloambound weapon back has two issues that affect aesthetics and gameplay.
The more serious one that I have encountered is the shield not appearing when weapons are drawn when running S&B. The character looks like they do not have a shield equipped. It is essentially a cosmetic issue, but when running content, not seeing a shield when you are trying to block as a tank is actually very distracting.
The less serious issue is with the stave and certain nightblade skills. There is a red glow that appears at the tip of the stave that persists when the stave is placed on the back. The stave disappears but the red glow is there just to the right and above the head of the player.
It would be good to know if these are known issues, and whether there is a timeline for them to be fixed. The Gloambound weapon pack will have generated a significant amount of income via crown store sales.