zroku

I found a fixed by changing the custom javascript to:

function replace(element, from, to) {
    if (element.childNodes.length) {
        element.childNodes.forEach(child => replace(child, from, to));
    } else {
        const cont = element.textContent;
        if (cont) element.textContent = cont.replace(from, to);
    }
};

replace(document.body, new RegExp("hello", "g"), "hi");

It all works now. Thanks.