I know there are multiple complaints on this forum about TT's brightness, but this one is a little different. When I turn on my ONE XL-S, the flash screen (custom) shows bright enough but immediately dims a notch, then sometimes dims further. This is during the day. I've increased both day and night brightness to max but it doesn't make any difference ... the dimming steps still occur. Sometimes it appears to be related to whether it was recently connected to my Laptop and whether I operated my TT using TomTom HOME, but I've not been able to establish a pattern. Has anyone else seen this behaviour?