Miscellaneous: Equipping issue

[Sareil]

12 Bard hunting wisps. If I have my instrument equipped and right click loot a lightstone it will equip in the primary slot, however, if I try to equip an instrument while a lightstone is in the primary, it will not equip. (instruments are 2h), trying to equip a lightstone with an instrument doesnt work either, it ONLY works when right clicking from the loot screen.