HP Omen RTX2060 black screen in CS GO after several minutes -> 144hz issue ?

[Gac3nty]

Hello HP Community

I have bought HP Omen laptop 15-dc1003nw i7-8750H 1TB+256/16G/W10H/RTX 2060. Everything was working fine for 11 monts, but 1 month ago I've started facing problem in CS GO (only game in laptop).

During game (15-45minutes) the screen goes black. I can hear loop of sounds, nothing on screen can be seen. Keyboard is working, i can turn to mute, I can switch on/off illumination. 
Only possibility is HARD reset to get the laptop running again. 

I've tried:

-newest geforce drivers (both versions - gaming and stable)

-newest BIOS from F15 to F19 update

-update of windows

-checking integrity

-re-istallation of windows (clean)

The laptop was sent to HP for checking. No issues found, for safety was changed the SSD HDD and re-installed Windows.

 It looks like some kind of 144hz issue. When playing in window mode no problems. Only full screen.
I've forced CS GO to 144hz, Vsync off/on, changing graphics resolution and settings - no luck. Please help.

[Gac3nty]

I think that the issue is the processor. In HP Command Center it is heating up to 97*C ... the max is 100*C for this processor.