BIOS seems to be read-only

[MCEStaff]

So a customer brings me this HP 15-ba057ca laptop, [serial number removed]  that wasn't booting... well, it tried to boot but even after many hours was still at a black screen, no cursor.

I tried to get to repair options to check the harddrive but the boot process would never get that far.

I tried booting from a USB Windows 10 installer in the HDD was unreadable. Still couldn't get to the installer (or repair tools).

So, to heck with the drive. Put in a new SSD, install Windows fresh (but strange, I had to manually select the file on the USB stick to boot from). Should be easy right?
Near the end of the install process it errors out with complaints about not being able to set the boot configuration.

A few retries and such later, I find I can finish the install by again manually selecting the boot file on the harddrive (after pressing F9 to select boot options). Find the bootfw64.efi file (or whatever the actual name is).

But there's no where in the BIOS to manually enter this. The command-line tools for configuring boot options don't work (BCDEDIT  ends up with "the request was aborted").

So, I tried to update the BIOS. Downloaded the files from HP (SP91389) and ran it. It fails, unable to update BIOS - with some Chinese text at the end.

Tried each of the files that the BIOS update wrote to a USB flash for me, none seemed to do anything.

[MCEStaff]

So I was going to ask whether there were any secret tricks to re-activating this BIOS. Jumpers on the mainboard, remove the battery, etc

But while I was write the original message, I tried running SP91389 again, and it got further. It said to reboot to do the actual update. It then booted into an HP BIOS Update program and the update seems to be taking place. 65% now.

[MCEStaff]

It looks like it is writing 2048 blocks, then verifying 2048 blocks, then it goes back to write them again. At least the 3rd time through right now...

OK. It just finished with the message that the update failed. Verification failed. Trying to restart...

[MCEStaff]

One other note...

I can't actually change ANY of the BIOS settings. I mean, I can change them, but once I select "Save and Exit", then re-enter the BIOS, my settings have reverted to what they were. No changes stick.

I can't change the language, enable Virtualization, set the "Action Keys" mode, etc.
So it again seems like the BIOS and the CMOS settings are read-only.

Thank you for any help.