Well, on mine it comes up in the previous-slider level.
When you press the backlight button?
I have 3 different generations of Legend C and on all of them, after switch-on the first press of the backlight button just displays the slider at 0, it requires a 2nd press to ramp it to the previous mid-slider level.
So, although it retains the preset level, it doesn't default to that level at switch-on, it defaults to 0. So turn prompts don't light up, it requires a clumsy 3-click sequence to activate this useful feature, each time you switch on.