Why does Ubuntu systematically resolve/unresolve a domain on the local network?

Question

Domain Name System

There is a local area network with several machines. Among them are working machines on Windows, my Mint, android devices, a server on centos 5. The tp-link router is friends with everyone.
A DNS server has been raised on the server, which determines our office domains. On the router, the IP addresses of the computers on which web development is being carried out are reserved by poppy addresses.
By DHCP, the router distributes settings to everyone. So I can go to the project1.anton.office address from any device to my computer, to the address http://project1.max.office, for example, to a colleague...
The problem is that on my machine, office domains resolve in about 1 second intervals with an interval of about 5 seconds. Those. for 5 seconds ping returns "ping: unknown host", then a second "ping anton.office (192.168.0.10) 56(84) bytes of data". And so in a circle. Those. it's not random.
I read everything on the Internet ... and lowered the MTU ... and manually registered the settings and specified DNSs ... unsuccessfully.
The problem is only on my Mint machine. There is a system unit with fedora, but it seems there were no problems before. There is no way to check.
I will be grateful for your responses.
PS I'm not a mega "you programmer", so I can write nonsense in the comments))

Answer 1

issue the command
nslookup anton.office
make sure that the DNS server to which the query is going is the one you expect
if this results in a timeout - look for a problem on the network. Using tcpdump or wireshark, check that requests go to the server over the network, that the server sees these requests and that the response goes in the opposite direction and the client sees this response
if the result is an error that the host was not found or a DNS server error, look for the problem on the DNS server itself. In the logs, check for problems when updating the DNS zone.
If there are no problems in nslookup - look for a problem with local caching of names.