monitor goes black when watching videos in dark/night

[xxxx526a]

whenever I watch video on youtube or play games my monitor will start adjusting brightness if its bright it'll go bright but if its dark it'll start going dimmer and when it's really dark. like a night time brightness will go down till monitor goes black and go back whenever it'll become bright in a video or a game etc: transition from night to day, looked online for couple hours trying to solve this issue done most of the things that r recommended like playing with power options , nvidia options all drivers are up to date. even took my gpu out and put it back in place (gpu is like a month old), it happened when I restarted my pc and it told me windows are configurating something don't turn your pc, same stuff what it tells u after an update and it started from then , I use intel i7-7700k, gtx 1080ti asus strix 470-f motherboard, Benq zowie xl2411 monitor

 

[sonjalcc]

My first guess would be Energy setting> ON,
cuz it reminds me of my šok when I noticed how dark it goes... Specially if you use dark theme or play darker games lol!
but then I guess it's named different ... Maybe than last layer does have some sort of tint o.0
just lemme know if it turns out to be SuM eko-ekonomi-atmo-frendli ŠiT