It will be easier to discuss this here rather than chatting
If I rephrase your question: you can't DHCP clients names. Is it correct?
This could be due to:
- leases not registered in DNS
- you type the wrong name
- DNS not used
In order to investigate, could you please tell us:
- what is the operating system for clients: from this we will look at what is really inherited from DHCP.
- what is you domain name
- what "search domain" is configured in DHCP
- what is configured in DNS. Any dynamic domain here?