I was actually having the same issue as well, so I decided to go looking through the script to see what was the matter. It turns out that the squiggly man dialogue is part of something else and that it jumped to that dialogue due to not having anywhere else to go. After the line "You look at the notes in your hand and finally understand," it seems that there was suppose to be a choice of whether or not you thought the poetry was great or not, but one wasn't there even though there was code programmed for after you chose. Since I have some experience in Ren'Py, I was able to code in the choice and attach it to the already programmed scenes they were supposed to lead to. After that I was able to get the ending to make sense and even looked at old videos of people playing through the game to comfirm that I attached the choices to the right scenes.