As you cast Arcane Orb with the Rune Arcane Orbit while walking thru a closed door it will create More orbs than usually. Basically Adding 4 without removing the remaining orbs. So it will show 7 or 6 of them instead of 4. If you cast it while walking Thru any Breakable Object Doors/Chairs/Tables/etc, during the casting it will create 4 ontop of the originals instead of removing it. I was able to reduplicate it 7/10 times.
Side note: I do believe this is only visual as for when one of the orbs explodes It removes the visual error. I didn’t notice any damage changes.