wrong body-classes (single and single-post) on page

I have created a website with a child theme (theme Baskerville) and created a new loop in it. I want to show only posts of a certain category on one page. The loop also works. However, the cards are displayed differently than on the blog or home page. In my loop the cards are stretched and the meta area seems to be broken. It took me a very long time to figure out that the body class of the page also carries single and single-post. if I delete these classes, the page looks very good; if the classes remain in the body, the page looks broken. why are the single and single-post classes carried in the body of the page? How can i delete these classes?