My Forerunner 255 is maybe 4 months old.
Just recently, not only does the backlight feature not work at all, but although it says the brightness for all settings is at 100%, I need direct light to see the display.
Sleep Mode is currently not on during the day.
Do not disturb is not on.
I have been in every setting and cannot fix this.
I also looked to see if it was a byproduct of the most recent firmware update and cannot track anything down on that front.
Anyone have any ideas?