Does a weapon that has been enchanted to do (insert extra damage type) count as magical to overcome resistances?
Is a magic weapon a magic weapon? See the Sage Advice Compendium: https://t.co/dh02JRnEH8 #DnD https://t.co/7e9NxsTawQ
— Jeremy Crawford (@JeremyECrawford) July 21, 2016
The answer refers to the old v1.14 of the SA compendium, that unfortunately still exists on the WotC website. Updated (v2.3) SA comp is at https://media.wizards.com/2019/dnd/downloads/SA-Compendium.pdf