What the Heck: Blank Login Screen?!

Can't think anything else but a Clean Install.
With Medicat recovery/diagnosis drive save all your data that is on the Optane to the HDD.
Do a clean install, deleting all all partitions on the drive.

Once it has installed, create a drive image backup and a rescue drive (use macrium Reflect or Aomei Backuper).

Hmm, I still don't see any attempt to prove this is not a hardware issue, at the least just to exclude that. (post #2).

From a different perspective, if you
a. image just your Windows partition

b. find a clean install boots reliably

c. you can hope that restoring your image of C: will give you back a fully booting system.

And if it doesn't, you will have demonstrated that your O/S (as in 'C: ' ) is corrupt in some manner.

Everyone, soon or latter, will face a drive failure. Don't be one of those that cry over a dead drive. Be prepared.
I do two kinds of backups: System and data backups.
I have separate drives for Windows + programs and another for my data. And a dedicated offline backup drive.
I do a System backup after a windows clean install and major programs installed. I use Macrium Reflect to do it.
I do a data update backup every week. I use a program called Vice-Versa Pro