RDP Session Sometimes Fail Authentication.

Hi,
I am having some issues with some servers at a remote location.  This remote location doesn't have a local DC, so authentication requests must cross an IPsec VPN tunnel.

The tunnel is working well with no errors to report.

Here is what I get from the Windows 2012 event log on the remote server:

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An account failed to log on.

Subject:
      Security ID:            NULL SID
      Account Name:            -
      Account Domain:            -
      Logon ID:            0x0

Logon Type:                  3

Account For Which Logon Failed:
      Security ID:            NULL SID
      Account Name:            USER1
      Account Domain:            mydomain

Failure Information:
      Failure Reason:            An Error occured during Logon.
      Status:                  0xC000006D
      Sub Status:            0x0

Process Information:
      Caller Process ID:      0x0
      Caller Process Name:      -

Network Information:
      Workstation Name:      MYLOCALPC
      Source Network Address:      -
      Source Port:            -

Detailed Authentication Information:
      Logon Process:            NtLmSsp
      Authentication Package:      NTLM
      Transited Services:      -
      Package Name (NTLM only):      -
      Key Length:            0

This event is generated when a logon request fails. It is generated on the computer where access was attempted.

The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.

The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).

The Process Information fields indicate which account and process on the system requested the logon.

The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.

The authentication information fields provide detailed information about this specific logon request.
      - Transited services indicate which intermediate services have participated in this logon request.
      - Package name indicates which sub-protocol was used among the NTLM protocols.
      - Key length indicates the length of the generated session key. This will be 0 if no session key was requested.

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I know the user/id password combo is correct.  I've tried with multiple user IDs.  If I logon to the console using the same credentials it works... then when I retry the RDP login, I have no issues.

It is very strange.  I'm not seeing any errors or failures at the domain controllers.

Any ideas?