Child theme edu-clean doesn't overwrite?

Hi Team,

I've a question about the edu-clean theme. We did several adjustments to the CSS and theme-options.php. For example we add some new color-boxes for the theme designer. That works fine.

But with the update we lose all the adjustments. Now I put these in the child theme, so we will not edit the core of edu-clean. It's that right?

But, the problem is, that I won't see the adjustments of the Child theme? So the CSS of the core will be used instead of the child theme CSS.

Do I something wrong? See the attachment.

Thank you in advance!

Cheers, Stijn