@Saamhraut -- I VERY MUCH DOUBT that any BIOS UPDATE will be helpful. There are far too many postings on this discussion board of "failed" BIOS UPDATES that have turned the motherboard into a "brick". My recommendation is to NOT update the BIOS, especially not as the first step.
So, power-on the computer, and enter BIOS SETUP.
Does it list the M.2 device, the NVME device, and the SSD device? It should.
When you exit from BIOS SETUP, you will only see a list of devices that CURRENTLY are bootable.
Any "empty" device (no files on the device) will not be listed.
When you launch the Windows Installer (from DVD or USB memory-stick), you should get a list of your devices that the Installer can use as a target for the installation of Windows. Correct?
Be alert for scammers posting fake support phone numbers and/or email addresses on the community. If you think you have received a fake HP Support message, please report it to us by clicking on "Flag Post".