Performed an OEM reset on nitropad.
Deleted old pgp key on nitrokey pro.
Created new pgp key added to nitrokey; exported public key.
Currently see this:
The red light means the device has initialized properly and has a contact with the smart card inside. This is good.
Besides the Nitrokey Pro, you need any USB flash/memory device with the public part of the GnuPG key, complementary to the private part you have on the Nitrokey Pro. Using both the BIOS will be checking for the data integrity.
Please insert the USB device with your backup of the public key.
Could you tell me why do need to add the key by hand? What error message do you get?
Adding the GPG key to the BIOS should be taken care of while the OEM factory reset was executed I believe.
Do you have the GPG Management Menu window opened by itself on boot?
I wish I came back here and wrote how I reached the solution those weeks ago, in case anyone else has a similar issue. I was exhausted after this gauntlet and once I resumed working with/on Qubes, doing the right thing by posting the solution on here escaped my mind.