"yesterday night it was working.. good colors and i was able to see all the first row of black boxes"
--> So it was OK, but not anymore this morning.
Possible explanation :
-Color profile is no more applied, do you let xrite profile checker to load at windows startup? you should keep it enable.
-You did change brightness settings under windows.
-None of the above, and in that case it could be :
--> CABC feature on your screen, see here : https://www.ecnmag.com/article/2010/04/content-adaptive-lcd-backlight-control (good for battery, awfull for screen quality!)
To know if your screen is CABC enable, make this test here :http://tylerwatt12.com/dc/
--> defective screen : ask Dell support for a replacement.
By checking in the intel control panel it dynamic contrast should have been enabled, but i did the test at the provided link and the image on white backgorund appeared instantly. Then i disabled dynamic contrast & all the other things that could give some problems, retried and it was the same.. no dynamic contrast.
Went back to lagom screen test and the first row is still too dark to be seen.
Yes, i changed brightness via keyboard shortcut. But when i try the lagom screen test i set it to 100%. No other slider used (such as the intel's one or other...).
The screen is FAR to be perfect and not defective, but this looks more like a software problem, not an hardware one..
And yes, i kept calibration loader at windows startup. Even if i redo the calibration nothing changes..
If i set gamma: 2.2 in the calibrator software, the thing goes worse. If i set gamma srgb it get a bit better but the first row of black boxes is still too dark.
If you don't use fancy software, and you just have intel graphic drivers and x-rite software, I can't find a reason why you could have any problem.
I'm calibrating monitors for years, never experienced such issues.
You said : "And yes, i kept calibration loader at windows startup. Even if i redo the calibration nothing changes.."
--> Yes, because the profile is not the problem, the problem is something has changed since your working calibration. It could be brightness, contrast, software color enhancement, etc...
Hard to tell without having your XPS under my hands.
I gave it a last try.. i uninstalled dell's version of the i1Profiler, restarted and all calibrations were gone.
Then i installed i1Profiler (the official one) and calibrated again on sRGB and 100cdm.
It worked! Colors ok, blacks ok.
Then i restarted. Here we go again.. all black are too dark. There is something interfering with the calibration loader.. Now if i re do the calibration, nothing will change until i uninstall the sofrware, restart and redo all the steps.
Have you removed DPC properly? It tends to switch color profiles at certain events. It might as well be due to Intel graphics driver resetting something?
Anandtech 9560 review mentions sth fish regarding colors.
Yes.. DPC is absolutely uninstalled. Intel settings that may affect colors are all disabled. Intel drivers updated to the latest version (8 january 2018). Nvidia drivers are updated to the latest official version, more recent than the one provided on the dell's website. I can downgrade it, but i don't think that it would solve the problem.
I have no other software installed that can affect color profiles.. i don't really understand.
When i go to the windows color profiles settings sometimes i get a strange error message saying that the device page has changed and something else.. i will post a screenshot