Question, why do you have the fan come on when the light is on and time out after 15 min and then also use this blueprint. The idea of this blueprint is to turn the fan on when you have a shower and off when you are done.
If you would like the fan on every time the light is on why not just use that and when you turn off the light turn the fan off and or have a delay to turn the fan off when you turn the light off. You can use my other blueprint to do this Toilet Exhaust Fan with time delay