I think the problem is not located in the server but the client. Did you set up the default domain search correctly? You do so in Yast -> network devices -> nameserver and hostname -> default domain search (retranslated from german version). Put home.lan in there.
What does this mean? Normally we resolve full qualified domain names as windows.home.lan. If you like to short cut this for local networking you tell your DNS-Client to add the domain name whenever you search for only the host name. So in your case you type “windows” and “home.lan” is added automatically.