bootrec /rebuildbcd finds "0" Windows installations

I have been running through several problems in the last days with my partitions and boot. I had dual-boot with Windows alongside Ubuntu, but I needed to remake everything again. This is the problem now:

My computer boots fine to Windows (no problems so far). Also, it access the GRUB menu fine, where I can boot Ubuntu without problems. Everything seems fine, but I am sure that there is something broken with my Windows installation.

I have a Recovery USB. When I boot from it and go to Troubleshooting > Command Prompt and run the following commands, I get the following results:

bootrec /fixmbr -> Operation done succesfully.
bootrec /fixboot -> Access denied.
bootrec /rebuildbcd -> Total identified Windows installations: 0

I have been thought different solutions that I found in internet without success. For example, this one. However, attrib c:bootbcd -h -r -s, I get Path not found – C:boot.

I though that It could be related to the EFI bootloader, that I need to repair, maybe?

As I say, the computer works, but I really want to understand why it shows 0 Windows installations. I do not want to bring problems with this in the future. Thank you!

This is my diskpart volume info:

diskpart