Samba share works with IP but not with hostname

Hi all,

I am not able to mount samba shares on a specific server using the severs hostname, only by using the IP address. I hope that someone more experienced can help me solve this problem.

Environment:
- samba on RHEL 7.4.
- DNS: The server is in DNS, and name resolving works forward and backward.
- AD: The server has joined the domain.
- Kerberos has been set up and works. I can log on using kinit, and klist displays a valid ticket

smb.conf:

[global]
    workgroup = 
    realm = 
    netbios name = CLIENTNAME

    security = ADS
    encrypt passwords = yes
    password server = *

[share1]
    ....

Error message on windows when accessing \clientname:

\\clientname is not accessible. You might not have permission to use this Network resource.

The target account name is incorrect.

Mounting works using "\IP\".

This identical setup has been used on other servers here, and they work fine. Only this server seem to have a problem. Any suggestions, anyone?

\Gunnar