JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="ChatBox1" placeholder="ChatBox1">
<input type="text" id="ChatBox2" placeholder="ChatBox2">

JavaScript

function handleVisibilityChange() {
    console.log(document.hidden);
    if (!document.hidden) {
        chatFocus();
    }
}

function chatFocus() {
    document.getElementById("ChatBox1").focus();
}

document.addEventListener("visibilitychange", handleVisibilityChange, false);
document.getElementById("ChatBox1").addEventListener("blur", chatFocus, true);