I experienced the same problem, but it appears even after Mirkon tells you about the place, and also after you speak with Mol. First time I got there after Mirkon told me to speak with that mute child, I persuaded him to show me the door and then both mol and Mirkon were spamming. So I reloaded and told me the mute child to show em the Dragon's Lair. Then Mol would speak to me but Mirkon was still spamming.