Hi @Sasiccia84,
The ZenBook behaviour with the moded BIOS is a little strange … but maybe it is normal for such modification.
I’ve checked my ZenBook a few minutes ago:
- I didn’t found info about my NVMe drive in BIOS.
- I can’t boot from my NVMe drive, but …
- … I can boot from “Windows Boot Manager” installed on my NVMe drive (in UEFI mode).
And as I remember from the past, when I installed Windows 10:
- When I started laptop from pendrive in UEFI mode then it was possible to install system on the NVMe drive and then boot.
- When I started laptop from pendrive in the old “BIOS mode”, the Windows said that it can’t be installed on the NVMe drive.
I think important: When I started working with my ZenBook I boot it from the pendrive with Macrium Reflect Rescue Media. And as I remember, the NVMe drive was visible there even before BIOS modification.
And the last but not least. Look at this post: [HowTo] Get full NVMe Support for all Systems with an AMI UEFI BIOS - #7275 by marcinkk - it was a real challange to install system on this laptop. As I wrote there: I’ve installed it on VirtualBox, then copied to the NVMe drive with Macrium and then booted successfuly.
BTW: After another few tricks I have upgraded system to Win11 22H2 some time ago 
Works flawlessly
Regards,
Marcin
PS. In the post mentioned above I wrote " the disk was seen in the BIOS" but in this post, after checking, I wrote that there is no information about NVMe drive in BIOS. I think it depends on other BIOS settings, but I’m not sure 