Do you have auto brightness on? In dim lit rooms it will dim the screen. Too much for my liking so I don't use it.
You could try getting the settings from someone that had their TV calibrated. Usually Rtings or avforums has that info.
Not sure about the Philips, but on some 4k tv's brightness actually refers to black levels. It might sound counter- intuitive, but try turning the brightness down.
Tweak the Gamma setting
Well I have a Phillips ambilight 4k it's not amoled. I've always had problems of the HDR content on it. it was always too dark no matter what I do the settings, I just don't think the TV is good enough to do HDR properly. My solution that changed everything was my Nvidia shield TV pro box. It has a setting in it to turn off HDR content and everything just looks great the normal 4k with no HDR.
Had the same problem with my LG OLED, I think it is the show's fault
What are the brightness, contrast and backlight settings? Also what source are you getting the dark image quality from? Is it a smart tv app or and actual hardware source?
I have philips OLED706 and I also found watching regular HDR10 content to be too dark most of the time. I think it has nothing to do with resolution being 4k.
I tried some Dolby vision files through plex and it did make the images a lot brighter (I compared the same file with DV on plex and then with HDR10 on Windows). As I understand it Dolby vision and also HDR10+ have dynamic metadata where every scenes brightness is adjusted independently, thus looking better. Regular HDR10 only has static metadata and the scenes are not adjusted independently which leads to many scenes being too dark overall.
I now only use either SDR or Dolby vision/HDR10+ and I’m fine with that.
There is also this very informative video:
https://www.youtube.com/watch?v=XPzM3NDGuSc
This ep looked really dark on my X90H so I'd think it's just the way they mastered it
I faced the same with 4th episode, It's too dark in HDR Can someone tell if that's the way HDR content looks or any change in picture settings?
An HDR test card might help ..YT has info .. I found sometimes skin tones were like they were over saturated..does take a while to get the colours Sony recommended setting it up on a SD channel on my tv ..
That backlighting isn’t helping anything