Strange issue. Haven't seen anyone else with this issue. nslookup.exe is an important part of Windows and rarely causes problems. The file nslookup.exe is located in the C:\Windows\System32 folder. You may just have a cursed installation of 10 and might have to reinstall Windows to fix this issue permanently or just keep task manager opened permanently to temporarily fix this issue.
Overall, this doesn't seem to be an Atlas OS issue for now because you are the first ever case of this issue, I'm treating this as a Windows 10 issue.