Nav/display screen brightness question
 

I like to run with parking lights and/or headlights in the daytime. When I turn on the lights in daytime the nav/display screen automatically switches to dark night mode. Of course, if you are wearing sun glasses you then cannot see the screen. Punching the day/night button does not change the screen back to bright daytime screen.
I've check the nav manual and don't see a fix for this. Has anyone found a way around this problem or an obvious solution? I apologize in advance if I missed something in the manual.
Thanks