Crafting/affix bug?

I put this wand in Catarina's crafting headstones to see what I could add, and it won't let me craft Spell Damage on it because it "already has a mod of this type". It doesn't have spell damage anywhere on it, except the implicit.

I spliced together two screenshots since I wasn't able to mouseover both at once.



Also I was able to craft cold damage on it, alongside the 73% cold damage. Now it looks like this:



What's going on here?

i have the same issue with a staff. it only has %cold dmg, added cold dmg to spells and mana regen, but the crafting bench says %spell damage is already on the staff. it also says %cold damage is already on the staff, so a difference to your bug. i think the problem is the %cold damage that is bugged and blocks %spell damage.