Nope, I didn't have this issue! Maybe trying contacting [email protected] or report it at https://repl.it/bugs!
Edit: Looks like someone else got this issue with html,css,js https://repl.it/talk/ask/Site-takes-long-to-load/19137
One of my students is having this problem working from home. It looked like he was getting a certificate error. My best guess is that its a problem with his browser security settings or his firewall. I submitted a trouble ticket with the school network administrator, so we'll see what he says.