I will relate an experience I had, and perhaps you can glean some common issue with what you are doing.
Since I have used Linux for some years (and am still not nearly as Linux knowledgeable as some others posting here) I use Legacy Mode. I have trying to use a Alienware 15 R2, (Skylake processor) which has an 256 gb M2 drive, and a one terabyte spinning drive. This is a old laptop, and I have installed a lot of different things to it. It was being odd, Which might be something with a Qubes install, or a hardware problem, and I wanted to isolate the possible reasons. Find what works, what is left must be the problem. I formatted the M2 to be blank with Gparted.
I installed the latest Windows 10 to the spinning hard drive, and updated Windows 10 to run the Dell Online Diagnostics. Which I spent a bunch more time installing the latest Firmware.
I tried to install the latest Qubes 4.2, where from a USB key, and it did the Qubes verification. And then. seemed to stop.
So I installed Qubes 4.1.2. Seemed to go all right.
I did the power down through Qubes, and it started Window s 10. Seemed like it was only going to see the Windows 10 drive to start on. Problem was, that I had, in the BIOS/EFI had left the setting to EFI. I changed that over. Had Secure Boot off. and it was in Legacy mode. then it would start Qubes 4.1.2
I have several security violations in this. One I should not have Windows 10 on the second drive while thinking this might be Secure. Whether the Qubes Install was made in EFI mode or not? Obviously not. I am not sure of all the implications of whether I should be using EFI, or maybe it really still is in EFI mode. But unless I put BIOS/EFI into Legacy mode, it would rather start Windows 10. If I did not have Windows 10 on the second drive, I guess it would hang.
I am lazy. If I were you. I would consider trying to install Ubuntu. And perhaps try to install version of Linux that needs Virtualization, and gives a good error message as to that - Virtualization is or is not working. That would test whether the Virtualization is working, not sure what Virtualization not working would look like to you? Where it would stop?
But you have more Linux experienced folks than myself helping you.