On multiple characters, on multiple realms, I have had auto-loot fail when looting the corpses of dead bugs. It doesn’t happen every time I loot, put pretty much at least once on every character I have. It is not consistent. Sometimes it is the first bug corpse I loot, sometimes twice on the same alt, but it has happened with almost every character I have when I do the quest (and that is quite a few, the last time just happened with my character Ofre on The Scryers).