Backlighting and sun light

Hello,

Should we leave the backlighting permanent to navigate them outdoors in the sun ? Because if I leave 15s as on edge 1030/1040... we no longer see anything on the screen after 15s, it's almost completely black because even the light is not on automatic, at the end of the backlighting time, the light drops to a minimum.

I have firmware 10.18

Thanks