How system determine who own the dns record

I have DC with DNS and DHCP service enabled;

DNS hold one active directory intergerated primary zone of my domain and using dynamic update with secure only;

DHCP is selected "Dynamically update DNS A and PTR records only if requested by the DHCP clients" on DNS tab;

The DC computer account is member of DnsUpdateProxy security group.

All of the clients are dhcp client;

I find most of the dns records owned by the "system"(system) and few owned by their computer account(computername$);

The "system" account own the dns record event when I manual set an ip address on the client.

I think it is not by designed behaviour.

How can I remediate it?