CommentStreams:C073d134e5eacd07ecf6ec7b06e02d6c

I suspect that in case of location 46 you are being defeated easily due to your hero's low HP (see Leveling (Hero)), so that Volcano Heart' Fireball is able to dispose of your cards before the main attack, which results in direct hit and defeat. Event mini bosses are known to be tricky sometimes, so, imho, it is not unusual.