Running Win10 IoT LTSC
Specs: Intel 9900K, Asus Strix Z390i, Intel Arc A750
I can't get the iGPU to output HDMI in Windows as long as the Arc drivers are installed. I get output from the iGPU HDMI in UEFI. If I set the main display to integrated and only connect to the HDMI, windows will hang at boot until I plug something into any other port, at which point the HDMI output dies and the other displays work. Windows sees the display, I can drag windows to it and adjust resolution, but on screen I just see NO SIGNAL.
Have tried:
DDU -> install Arc drivers -> install iGPU drivers -> Arc drivers get uninstalled and iGPU works on DP only
DDU -> install iGPU drivers -> install Arc drivers -> Arc works and iGPU gets uninstalled
DDU -> Install Arc drivers -> install iGPU drivers via .inf file -> Both drivers show up in device manager, but no output from iGPU HDMI, DP works. <--- I am here now
BIOS settings are all correct.

Am I just fucked? This exact setup used to work before Intel did a big overhaul of the Arc drivers (moving from Arc Control to Intel Graphics Software), but now I seem SOL. Officially, only 10th gen and newer Intel are supported for use with Arc, but 10th gen has the same exact iGPU as 9th gen..