Dunno if it applies, but I recently discovered - and resolved - a bug myself. If you transfer a completely uninfused, unupgraded sword from the character you get it on to another character in the middle of an exotic sword quest already and upgrade/infuse it on THAT character, it will wait for you to complete the current phase of THAT exotic sword quest and then give you the Essential Elements phase of the new sword's quest. That's right, as far as I'm aware, it skips all prior requirements for the exotic sword questline before the phase of the existing quest you already had, for the new one. No crucible kills for my void edge! It was honestly an accident.