It's been a while since I last used renpy, but I hope this helps! If I'm mistaken, a pro can step in.
The current nvl textbox is quite small. With your setup, players need to scroll using the mouse wheel to read everything.
Edit the nvl screen in screens.rpy (or maybe gui.rpy/options.rpy). You're looking for something like this:
Python:
screen nvl():
window:
id "window"
ysize 400 # Look for ysize and increase it to make the box taller. This should fix it.
By the way... For narration, it’s better to define the narrator like this:
Python:
n = Character(None, kind=nvl, clear_window=True)
Because by default, nvl mode stacks all previous nvl dialogue lines unless you use nvl clear. This works well for things like email or text messaging simulations. Now, using clear_window=True makes the textbox clear automatically for narration, which is what you're aiming for.
Best of luck with your new game! If this isn't a troll, don't hesitate to reach out for more assistance.