Failed to join domain: failed to lookup DC info for domain 'HCPI.HQ' over rpc: {Operation Failed}

Server: Synology NAS with Linux DRM
Client: SLED 15.2
Network. AD network via SAMBA
I get this failure and can’t see the network. I can ping the server, I can add the drives via smb or NFS, but I can’t see the network.

I get this failure when accessing domain:
Enrollment has completed successfully! Command output: Using short domain name -- HCPIN Joined 'SLED15DESKTOP' to dns domain 'hcpi.hq' No DNS domain configured for sled15desktop. Unable to perform DNS Update.

… I used so far:
I put a line
like the following in my /etc/hosts file hostname.domain.local hostname
Now my Compoter get resolved and the failure about doesn’t appear. Enrollment is fine.
SLED15Desktop:/etc # hostname
SLED15Desktop:/etc # hostname -f
SLED15Desktop:/etc #
But network is still not visible

@HANS-CHRISTOPH Hi, loopback ( should only be localhost hostname.domain hostname

Remove the .local entry

using net ads join -U <domain admin> -S <FQDN of DC> I can add the domain
But still…