I changed the WiFi NIC in my notebook. After that I discovered that the new NIC did not have access to the saved WiFi secrets that where saved prior to chaning it.
I ran a well known utility from NirSoft, wirelesskeyview. Thank you again, Nir.
The utility confirmed what was easy to argue, that the keys are still saved in the computer, but they are associated with the old adapter (see the Adapter Guid):
Reassociating the old keys with the new adapter is indeed very simple: just select all the keys you want to “restore” and export them in a text file. Then simply import the same file. It is not necessary to modify it in any way, because when you export a key in Wirelesskeyview, the adapter ID is not saved; and when you import it, it is imported in the currently used adapter.
After importing the keys, you can delete the old keys associated with the old adapter, if you’re not going to use it anymore.