Domain environment
Windows 10 : 1803
Windows update: controlled by Domain administrative

Solution:

https://answers.microsoft.com/en-us/windows/forum/windows_10-start/stuck-on-downloading-language-dictionary-chinese/294a70d2-fc51-426a-b7b9-d5557a466789#

REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU" /v UseWUServer /t REG_DWORD /d 0 /f
net stop "Windows Update"
net start "Windows Update"
control /name Microsoft.WindowsUpdate