what is causing the new UI to lag so much?

...I pretty much cant check messages nor have live chat open anymore when I play chess cuz it lags so bad like why does me trying to check my messages cause the entire site to freeze for a solid minute? and the live chat as well, why does it lag when I type there so much?

I haven't been seeing any major lag on the interface

I have literal jet lag with the notifications, I have to check messages 3 times to make the notif disappear