Sticky header not reducing size after latest wordpress and Hihgend update

Hello,

I have updated my blog to WordPress 5.6.1 and Highend to the latest (can´t find the number anywhere now).

After the update the sticky header is not reducing its size when scrolling down.
Also, a picture that usually matched fine is now appearing in a mosaic way.

Can you help with that?

My website is https://alfinlibre.net/

I have updated an screenshot with the issues.

Many thanks.