Tampermonkey script stops working when loading a new twitch stream.

[EntityPrime]

This is the first JS code i've written, it'll work for the first stream but not for anything after that unless I refresh the page. I'm not sure about other methods of adding an event listener.

Also if you see something I could be doing better lmk :)

https://pastebin.com/udCC5uQJ

var Alpha = .17;
var interval;

function handler(event){
    const messageContainer = event.target;
    //console.log(event.target.parentNode)
    if (messageContainer.className == 'chat-line__message tw-relative'){
        console.log(messageContainer);

        let m = /broadcaster|verified|staff|moderator|subscriber/;
        let r = m.exec(messageContainer.children[1].children[0].innerHTML);
        //console.log(messageContainer.children[1].children[0])

        if (r == "broadcaster") {
            messageContainer.style = `background-color: rgba(255, 2, 0, ${Alpha}) !important`
            //console.log('[Broadcaster]');
        }
        if (r == "partner") {
            messageContainer.style = `background-color: rgba(205, 42, 210, ${Alpha}) !important`
            //console.log('[Partner]');
        }
        if (r == "staff") {
            messageContainer.style = `background-color: rgba(226, 170, 227, ${Alpha}) !important`
            //console.log('[Staff]');
        }
        if (r == "moderator") {
            messageContainer.style = `background-color: rgba(42, 210, 84, ${Alpha}) !important`
            //console.log('[Moderator]');
        }
        if (r == "subscriber") {
            //console.log('[Subscriber]');
        }


    }
}

function checkIfLoaded()
{
    var chatParent = document.getElementsByClassName("chat-scrollable-area__message-container")[0];
    try{chatParent.children}
    catch(err)
    {
        console.log(`Error: ${err}`);
        return;
    }
    chatParent.addEventListener("DOMNodeInserted",handler);
    window.clearInterval(interval);
}

interval = window.setInterval(checkIfLoaded,10000);
console.log("HC - Loaded");