Description of Bug: If you type a lot of text and the speech bubbles overflow, they stop going away on their own and just hang around forever. I run into this frequently when giving lessons because I'm talking a lot. 
Reproduction Steps:

1.  Type lots of long dialogue bubbles
2.  Bubbles start disappearing to make way for new ones
3.  Eventually, they stop disappearing on their own and only do so when you say something new

Error message (if applicable):
Screenshots: