Can't Connect to Minecraft Realms

My friend made a Minecraft Realms server today. Everyone else is able to connect to it just fine but whenever I try to the loading screen goes to "building terrain" and then instantly goes to a screen that says "Connection Lost, Disconnected". I've tried everything, but it keeps giving me that message. My computer is fine, I turned both my firewall and anti-virus off, I've closed unnecessary apps, the world file is under 500kb, and my internet is fine. There's literally no reason this should be happening. Is there anything I can do?

 

I tried again today. A different friend made a different realm just to see if the problem was on the original friend's end. We tried it again and it still didn't work. Same error. It's obviously on my side but there's no reason why it should be doing this.