If this note is confusing, check the last Grab Bag for clarification:
Legendary weapons that were created prior to 1.70 were not able to be spell-crafted permanently from the recent changes made in 1.84. If a pre 1.70 Legendary weapon was spell crafted after 1.84, the spell crafting bonuses would wipe after zoning or re-logging. As such, the first three slots in Legendary weapons made prior to 1.70 now have their old bonuses (Con, Resist, Resist) back in those three slots.
For Reference, here is the 1.70 note denoting the change in Legendary Weapon stats:
Fletching & Weaponcraft - In response to player feedback, the constitution stat on Legendary Weapons has been changed to either strength or dexterity, depending on the type of weapon. As a result, the Spellcrafting gems required in the recipes have also changed to reflect the stat used on the final product. This change is not retroactive, so players who wish to utilize an updated version of a Legendary Weapon must seek out a Weaponcrafter or Fletcher to create a new product.