Why SN not working

Hi,
This is Corebook Serial Number printed on the box.
Refer the attached photo.
Support site https://support.chuwi.com/ does not accept it.
Why?
Is the site working correctly.
Thanks.

Not sure why. Have you tried using the one printed in the back of laptop? Is it the same?

Support fixed it. But it means it may not always be up-to-date!