Blank space before top bar when using child theme

Hello. When I activate the child theme, when I open the page the top bar appears displaced, and above it a large white space. That space disappears (the top bar moves up) when I scroll the page.

This problem does not occur with the parent theme, only when I activate the child theme. I don’t have any customization on the child theme styles. I have tried to correct it with this:

.page .post-inner {
  padding-top: 0;
}

But the problem persists.

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