ScrollPageModule.js

let tx_scroll_module = document.querySelector('body > .module');
if (TYPO3.settings.cache) {
    // v13
    tx_scroll_module = document.querySelector('body > .module > .module-body');
}

/* Prevents jumping after reload*/
window.location.hash = '';

const uid = new URL(window.location.href).searchParams.get('id') ?? '0';

window.addEventListener('unload', function () {
    sessionStorage.setItem('ext-scroll-pages-' + uid, tx_scroll_module.scrollTop);
});

const pos = parseInt(sessionStorage.getItem('ext-scroll-pages-' + uid));
if (pos) {
    tx_scroll_module.scrollTo(0, pos);
    // This happens, when the clipboard in V11 (loaded via AJAX) is appearing
    if (pos !== tx_scroll_module.scrollTop) {
        window.addEventListener('load', function () {
            tx_scroll_module.scrollTo(0, pos);
        });
    }
}