UHD 620 issues

I am having issues with my laptop, Acer Spin 5 SP515-51gn-80as. I installed Windows 7 using Uefiseven. I’m using the modified Intel UHD version 21.20.16.4839 which specifically works for my UHD 620 DEV_5917. I also get x264 video decoding/acceleration working by HEX patching the 2 dll files. I also tried with the Biostar version and also 21.20.16.4860. With other versions of drivers (the 2 UHD 630) I get video, but no working x264 video decoding/acceleration even with HEX patched dll files. The problem is something fails sometimes and I get a blue screen, but my screen goes black instead and I cannot debug. I am sure BSOD is not showing up, because I simulated one and I get black screen. While using Standard VGA I get BSOD showing up when I simulate one. I suppose the video driver causes issues, which causes BSOD which doesn’t show up. Do you guys have any ideas what I could further try? Maybe some other driver version? Thanks.