Why can a computer drop out of a site?

Question

Active Directory

The domain is divided into several sites. When transferring one of the computers from site to site. The computer refuses to see the new site. Constantly trying to knock on the old site and controllers. NLTEST /QUERY says there is no server logon. NLTEST /SC_RESET:DOMAIN\SECONDDC allows you to change the logon server, but only until a reboot.
Now I solved the problem using the registry key. HLCM\System\CurrentControlSet\Services\Netlogon\Parameters. I created the SiteName key and indicated the current site where SecondDC is located in it.
There are no problems with the network, the gateway is knocking. Until SecondDC is knocking. There are no problems with DNS, all records are there. There are other computers in this site, everything is fine on them and they immediately saw the new site and SecondDC. What can keep a computer in an old site?