Remove Page Title

I use the twenty twenty theme, a nice theme. I use Extra CSS to remove the page titles, with a white background.

It’s working fine, except on a smartphone and except in the blog (posts) part of the site. see: https://dovenschakenamsterdam.nl/blog/

This is the Extra CSS :

header.entry-header.has-text-align-center.header-footer-group {
display: none;
}
.header-inner.section-inner {
padding-bottom: 0;
}
article {
margin-top: -4em;
}

Looking for a solution …….

The page I need help with: [log in to see the link]