Yeah, I’m really, really sorry! I don’t have a good solution to this! When you hit the down arrow the next line doesn’t bold but does it at least play a little sound effect? If it does, even if the next line isn’t bolded can you try hitting space to see if the selection is changed (I am assuming not). As a last ditch attempt you can try restarting your computer or restarting the game in a different resolution, but unfortunately I’m not sure what’s causing this.