[Theme Horse Support Team]

Hi wietsketammes,

It seems that your responsive layout is off. Go to dashboard-> appearance-> theme options-> layout options -> responsive layout and (check it on)

Then your responsive layout will be displayed.
And also it seems that you have customized the code. If you customize the code then we cannot help you to fix the exact issue. Just view in our demo site, if there is feature in demo site then we can help you other than it we are sorry you need to hire a developer to fix it.

Thank you!