Custom Credential Provider Not Showing in Sign-In Options on Locked LogonUI

Question

I’ve developed a custom credential provider for Windows 11 and followed these steps:

Successfully built the credential provider, which generated a DLL under x64/Debug. Moved the DLL to the System32 directory. Registered the credential provider using a registry file. However, when I lock the machine and go to the LogonUI screen, I don't see the "Sign-In Options" button. My custom credential provider should appear under this option, but it doesn’t show up at all.

Here’s what I’ve already checked:

DLL Placement: Ensured that the DLL is correctly placed in C:\Windows\System32. Registry Entries: Verified that the registry keys were added correctly under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\Credential Providers and that they point to the correct CLSID and DLL path. Build Configuration: The DLL is built in x64/Debug mode, matching the system architecture. Signatures and Security: My DLL is not signed. Could this be the issue?

Questions:

What could be causing the "Sign-In Options" button not to appear? Are there additional steps or checks required to ensure that my custom credential provider is activated and recognized by the system? Is there a requirement for the DLL to be signed or any specific permissions needed? Any insights or additional steps to troubleshoot this issue would be greatly appreciated.