smbpasswd failing with NT_STATUS_LOGON_FAILURE

when smbpasswd fails with "Could not connect to machine 127.0.0.1: NT_STATUS_LOGON_FAILURE" the issue is that the old password you are using is incorrect.

smbpasswd
Old SMB password:
New SMB password:
Retype new SMB password:
Could not connect to machine 127.0.0.1: NT_STATUS_LOGON_FAILURE
Failed to change password for

The old password being used is incorrect resulting in a failure to log into the machine to change your password.