Why does React app rebuild?

Question

Express.js

The application uses NEXT.JS for the front, SSR for EXPRESS.JS. All links are made in such a way that the application does not reload when clicking on them (as it should be in React). But I noticed that when I press the forward and backward buttons of the browser, the application is rebuilt again. Why is this happening and how to fix it?
PS Added the following code to the pages/_app.js file (according to the advice of the English-speaking forums):

componentDidMount() {
        Router.beforePopState(({as}) => {
            location.href = as;
        });

    };

But it did not help.