You might check for basic connectivity to your smb server with smbclient.
Here is an example:
$ smbclient -e //smb3enc.somecompany.com/shush -U nt_username -W dom -mSMB3
Enter DOM\NT_USERNAME's password:
Domain=[DOM] OS= Server=
smb: \> quit
Note the above call requires encrypted smb3. The smbclient binary will allow you to get and put files similar to FTP.
This gives me a similiar error - session setup failed: NT_STATUS_NO_LOGON_SERVERS
I would suggest that you break the domain connection and define a local password file. Get a working configuration that you can open with smbclient, then try to map from a Windows client.
I don't have enough experience with Samba integration in Active Directory to help you debug the Kerberos setting.