where did you receive it from? first thoughts would be maybe grower didnt flush, heavy chem. nute buildup? if its off the street then maybe it was dusted/sprayed with something to give an effect to the user or to have treated a pest problem during grow. but then again, u can get something dusted at a dispensary as well if it somehow gets past whoever checks it.
if you have more, maybe do the same process but use something besides parchment paper. could have been the paper itself? wife didn't hit the oven with cleaner a few hours before right? heh
i wouldn't think the strain would have that as a characteristic but i have no experience with it so i can't rule it out.