// Create container
const container = document.createElement("div");
document.body.appendChild(container);

// Create child
const child = document.createElement("p");
child.textContent = "Hi";
container.appendChild(child);

// Create comment node
const comment = document.createComment("");
container.appendChild(comment);

// Query nodes, it returns "['Hi']", as expected
console.log(document.querySelectorAll("p").map(item => item.textContent));

// Try to move node
container.insertBefore(child, comment);

// Query nodes, "['Hi']" expected, but it returns "['Hi', 'Hi']"
console.log(document.querySelectorAll("p").map(item => item.textContent));