Wrong / unsafe cert warning means you haven't installed their certs. They're trying to mitm you, but your browser is protecting you. It's almost certainly SNI,

Wrong / unsafe cert warning means you haven't installed their certs. They're trying to mitm you, but your browser is protecting you. It's almost certainly SNI, it's the plaintext hostname. Servers rely on it being present to route, so the only way around it is to tunnel through the firewall with a vpn