The seasonal tasks for "Defeat Murkwood bosses" (both 5 and 10 bosses) seem to be counting task progress based on how many bosses have been fought rather than how many have been defeated, despite the tasks and their descriptions clearly stating the bosses need to be defeated. Not sure if the tasks are counting progress wrong, or if it was changed to "Fight Murkwood bosses" and the text for the tasks wasn't updated (though I didn't see anything about this in the patch notes if that's the case).