Why can't I add spell damage to this wand?

Bought this wand from another player, thinking I could craft spell damage on it, since it has an open prefix and doesn't already have an 'increased spell damage' mod on it (except as an implicit).



However, when I put it in Catarina's lvl 7 crafting table, both of the 'increased spell damage" options are in red and says "This item already has a mod of this type."



I figure I should report this, because it obviously doesn't have an explicit spell damage mod on it.

Maybe something about the new 'Topotante's" mod is flagged incorrectly, preventing the master crafting of increased spell damage?

If someone knows what's happening, let me know. Is it a bug, is it intentional, did I miss something obvious?

I'd love to use this wand, but really want to craft spell damage on it rather than faster casting or some other prefix.

Thanks in advance.

Some mods on items are intentionally mutually exclusive and that is almost certainly the case here. The explanation on the crafting bench could be more informative though