Where does the error appear when issuing dhcp?

Question

DHCP

There is a local network, there is a domain (vin2008 server) and a dhcp-server on the domain. Everything connected and worked fine. Range 10.0.0.0/24.
SUDDENLY on one computer (vin7 pro, is a member of a domain), right on the go, the preferred dns server became 192.168.0.1, and not the domain address. After release/renew everything is restored. In the morning everything works, and then in the afternoon right on the go SUDDENLY the address changes.
Checked for viruses, nothing interesting.
When changing dns, the dhcp server from ipconfig points to the correct domain and dhcp server, only the primary dns changes.
What can change the primary dns in such a strange way?

Answer 1

What's in the dhcp server logs?

Answer 2

As an option, there is another dhtsp server on the network. 192.168.0.1 is a popular address on all modems/routers/wifi.