Windows Server 2012 R2 Remote Desktop Unaccessible to Users

Hi everyone.

Right now, I'm having issues with my server, running Windows Server 2012 R2 not allowing users to remote desktop to it. Me as a client will get Error Code 0x4

When looked into the errors in Event Viewer in the server, it always produces ID 36874 and 36888, which related to Schannel/TLS services.

I have tried multiple solutions like restart the server's remote desktop service, add TLS 1.2 to the servers regedit, update my Windows Server OS, change policy group in Computer Configuration -> Administrative Templates -> Windows Components -> Remote Desktop Services -> Remote Desktop Session Host -> Security, specifically "Require use of specific security layer for remote (RDP) connections" policy.

The previous methods didn't have any luck, but with the last method I manage to log in the server (let's say my username is User A) with RDP as it's Security Layer but other users (ex: User B) require a smart card. Although it seems resolved, I believe this is not an optimal solution.

I wanted to enable the server to allow remote access from any user with privileges (User A & User B) without trying to adjust more in the regedit or the group policy editor further to avoid my server to break because it's a production server, currently going live.

Is there any option I can try to ensure this issue won't happen in near future?

Regards,

Ahmad Dhamiri