as title, press the screen icon top left and day/night mode etc comes up
i press the brighter or darker buttons but nothing is happening for me 
was happening on v6.2.2 so just upgraded to 6.7.1 and still same so am wondering if the issue is my end
Probably windows related. Maybe this old thread can help. Brightness changes when agopen starting
no,that didnt help
i manually adjusted screen brightness from windows settings so all is good,just dont know why
Do you have another app in Windows controlling the brightness? Dells usually have they own brightness control. They don’t play well together
Whatever the fz g1 uses🤷♂️