Weapon invisibility while in combat

[circuitnerd.5863]

So this bug seems to be pretty specific but I'll do my best to explain. Currently I'm using Greatsword (first set) and Scepter/Shield (second set). I'm playing Guardian. Now if I go into combat with my second set and swap to the first, my Greatsword is invisible. However if I first start out attacking with my Greatsword and then swap to my second set, everything appears fine. It's only if I go from second set to first set while in combat. I currently have "Show weapons" both uncheckmarked. If I simply draw my weapons though while out of combat, everything appears normal.

As you can see in this screenshot my Greatsword is invisible.