Hola P
I checked but all questions for that lesson are correct in the system, all answers requiring "por qué" have the option with the accent. Could it be you missed the one with the accent? I checked the one you answered on a kwiz you did today where you chose answer "por que" without the accent but the option with the accent is in the menu. The question was this one:
¿___ hacéis tanto ruido en clase?
Why do you make so much noise in class?
Saludos