AirPLay / display mirror problem on HP 8470 HighSierra

I just installed to my friend High Sierra to a HP8470 laptop with 1600x900 display.
Everything is OK, but the displayport(hdmi) output does not work !
In BIOS the UEFI is set "withoput CSM" . I also also tried to set to hybrid, but no difference... No "AirPlay" / Mirror... It is very important, because he wish to use the laptop for presentations too.

My 6460b works perfectly with mirroring display, but it is only low resolution display machine. So, I think the problem is with the high res. display setting. I have no idea, and no experience how to persuade this 8470 for mirroring.

THANKING your all ideas fix this problem ! (may be some extra kext needed, or clover setting ?????)

... there is no discrete video chip, just Intel HD 4000 video is built in ...