Too bad a copy wasn't recognized on the HDD either. It used to be it would be recognized for me, but one made in the course of this thread is not seen by Backup & Restore for a restore. (The original is seen, &, a week/so ago, I did restore an original). Too bad putting a new image into the copied WindowsImageBackup folder didn't make it visible either. i haven't tried this time around, but it used to be I could make a new original into a copied WindowsImageBackup folder. But I gave it a devicename folder of its own (that's the first folder inside WindowsImageBackup) which made it separate & distinct (I explained above). It then looked better than the copy in some of the restore screens, but both it & the copy did show up & were willing to restore. I backed out, but Slance, in that same ancient thread, did restore them with some success, IIRC. But I ended up not trusting copies.
If even the originals don't work for you, what makes you think a copy of it would work anyway? It looks like the Security tab you are showing is an original because it has Account Unknown in it (which my original has) & it has Backup Operators in it (which Slance has). However, it doesn't have Creator Owner in it, which both Slance & I do have in an original. It's odd we don't all three have identical permissions on an original. I can't explain it.
I tend to agree with Slance, you should start new & switch to a 3rd-party image maker. Your images are enormous, & the 3rd-party apps are far, far quicker with enormous ones. Also, they are more flexible in use, make more compact images, & can see partitions Backup & Restore may not (like my Dell factory reinstall partition which is gone now). But there is a huge manual to read & a learning curve.
As I said in my first post on p.1...
[But I must add, the first time you double-click a .vhdx, it may give an error message. So, just OK the error, & open Disk Management. The mounted image will have the same name C: had when the image was made, but no letter. Put a letter on it, & it will show up in File Explorer.]
When done copying files, remember to right-click the mounted letter in File Explorer, & select "Eject".