Remote Desktop Authentication without NTLM - How to Configure from non-Windows clients?
Solution 1:
Policy "Network Security: Restrict NTLM: NTLM authentication in this domain: Deny for Domain Accounts to Domain Servers" is restricting NTLM connections to domain servers. If you want to connect to domain via client which does not support Kerberos you have to disable this policy or maybe try option "deny for domain accounts". Other potential problem is that you have turned on NLA (Network level authentication). Try to turn it off and try again.