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.

[Taluvill]

I looted a greater lightstone the other day with my bard using his Mistmoore drums, and had no issues looting the lightstone. It went straight to my open inventory slot, which I did have one of those.

Maybe the fact that I had an open inventory slot made the difference?

[Sareil]

I definitely had inventory spots open, cause further stones went to them (both inventory slots and bag slots), but yeah, I had both an instrument and a lightstone equipped at one point. This occurred with both the mandolin and the hand drum.